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LERV1450 Instructor’s Manual

Engine Training

3500 and 3500B Series of Diesel Engines 2001

LERV1450

Introduction

Instructor’s Manual

Page 2

Lesson 1 2001

Figure 1-1 Introduction

Basic level training manual 3500, 3500B diesel engines Components, basic operation, D & A, adjustments

Instructor or self taught

This class book is intended to be a basic level training manual for 3500 and 3500B diesel engines. The material identifies components, covers the basic operation of the engine systems and covers some disassembly, inspection, assembly and adjustment procedures for the major areas of the engine. This manual can be used by an instructor to teach the information or it can be used by an individual as a self-teaching guide.

Figure 1-2 Displacement

1980: 8, 12, 16 cyl - standard displacement

1999: 12, 16, 24 cyl B series high displacement option 3524B engine: 2 3512B engines in a module

The 3500 diesel engines entered production in 1980 and have been available in 8, 12 and 16 cylinder configuration. All had the standard 4.3 liters per cylinder displacement. In 1999, a higher displacement option was made available in the 3512B, 3516B and 3524B engines for some marine, generator set and vehicular applications. The 3524B engine is two 3512B engines connected in series on a module frame which operates as a single engine.

LERV1450

Introduction

Instructor’s Manual

Page 3

Lesson 1 2001

Figure 1-3 Bore & Stroke

Standard displacement: 170 x 190 mm bore and stroke High displacement: 170 x 215 mm bore & stroke

The standard 4.3 liter per cylinder displacement engines have a bore and stroke of 170 mm x 190 mm (6.7” x 7.5”). The high displacement 4.9 liters per cylinder engines have a bore and stroke of 170 mm x 215 mm (6.7” x 8.5”). The high displacement engines are offered with 1500 and 1600 rpm engine speeds only at this time.

Figure 1-4 3500 Evolution

Phase 0 to phase II 100 kW/cyl to 140 kW/cyl EUI 1992 - machine Series B 1995 EUI phase I & series B MUI phase I High displacement 1999

The 3500 engine series evolved from a maximum rating of 100 kW/cylinder (135 hp/cyl.) to 140 kW/cylinder (188 hp/cyl) through the first three phases of production. In 1992, 3500 engines with Electronic Unit Injection (EUI) were produced for Caterpillar machine applications. In 1995, series B 3500 engines were first produced and offered to the market. The series B engines offered many improvements as well as EUI. In 1997 EUI was offered as an option on the phase I engines. Both phase I and series B engines are currently produced with EUI. Phase I engines can also be obtained with Mechanical Unit Injectors. In 1999 a high displacement 3500B engine was offered as an option giving further improvements to the product line.

LERV1450

Introduction

Instructor’s Manual

Page 4

Lesson 1 2001

Figure 1-5 3500B Changes

3500B changes

Camshaft 6 mm larger

Camshaft bores in block strengthened

Injector cam lobes and follower widened Valve lobes and followers narrower

Two piece piston: forged steel crown and cast aluminum skirt

Piston taller, elevated top ring

The 3500 B engines incorporate several mechanical changes in design that improve mechanical reliability, lower exhaust emissions, reduce smoke, improve fuel economy, permit higher ratings, and provide enhanced diagnostic and monitoring capabilities. • The 3500B camshaft is 6 mm larger in diameter than the previous 3500’s. The larger camshaft can drive the 20% high pressure injectors more aggressively and handle shorter injection duration. • The camshaft bore areas in the cylinder block have been reinforced to accommodate the larger camshaft. • The width of the injector lobe on the camshaft and the injector followers have been widened so durability of the camshaft and followers are not compromised. The camshaft valve lobes and followers have been made narrower to accommodate the wider injector lifter. • A two piece piston with a forged steel crown and a cast aluminum skirt provides excellent strength in the high load area and the aluminum skirt saves weight and dissipates heat. The deep crater maximizes the contained combustion. • The B piston is taller in height and has an elevated top ring that reduces crevice volume. These features help optimize engine efficiency to reduce smoke and emissions and lower fuel consumption.

LERV1450

Introduction

Instructor’s Manual

Page 5

Lesson 1 2001

Timing wheel: engine speed & timing signal

• A timing wheel has been installed on the rear of the left camshaft to provide an engine speed and timing signal to the Engine Control Module.

Electronic Unit Injectors

• The 3500 B engines use Electronic Unit Injectors. These are mechanically actuated by the camshaft and electronically controlled by the Engine Control Module. The injectors produce a 20% higher injection pressure for improved fuel vaporization.

20% higher injection pressure

ADEM II Electronic Engine Control and Monitoring System

Improved performance Easy monitoring and troubleshooting

• The ADEM II Electronic Engine Control and Monitoring system is made up of the Electronic Control Module (ECM) and a personality module that provides a signal to the injectors to control the amount of fuel for engine speed control and also vary the timing as needed. The EUI system is the major reason for improved engine performance, reduced fuel consumption, reduced emissions and startup smoke, and provides easy monitoring and diagnostic troubleshooting.

Injector helper spring

• The rocker arm base has been modified to provide for an injector helper spring. This spring exerts a pressure on the cam follower to keep the follower in constant contact with the cam lobe to reduce risk of camshaft or follower failure.

Rear gear train strengthened

• The rear gear train has been strengthened to drive the larger camshafts and heavier valve train. The gears have been widened and the gear pitch has been reengineered to add strength to the gear train.

Higher capacity high mounted aftercoolers

• Higher capacity aftercoolers are used and are located up out of the vee of the engine. Air is transferred from the aftercooler to the cylinder heads through a shorter, straighter path.

Larger capacity turbochargers

• Larger capacity turbochargers are used to accommodate the higher ratings and give more efficient operation.

LERV1450

Introduction

Instructor’s Manual

Page 6

Lesson 1 2001

Figure 1-6 3500B HD engines

1999 High Displacement 3500B 1500 & 1600 rpm 8% new parts

In 1999 a high displacement version of the 3500B engine was offered as an option on 3512B, 3516B and 3524B engines. The high displacement engine has 13% larger displacement and can be rated with 13% more power. The engine is offered with 1500 and 1600 rpm ratings only. Only 8 % of the HD engines is new content.

Low fuel consumption & cleanest emissions

This option offers lower fuel consumption and the cleanest emissions in the industry.

Stroke increased 25 mm

The stroke length was increased 25 mm (1 in.) with a corresponding increase in the crankshaft throw of 12.7 mm (.5 in.). The crankshaft has more material to handle the higher power loads.

Crank throw increased12.7 mm - stronger crankshaft Longer, stronger con rods

Longer connecting rods with stronger shaft geometry and a stronger pin end are used.

2 piece piston: shorter, modified crater

The piston is a two piece piston with a forged steel crown and an aluminum skirt. It is shorter than the regular 3500B piston and has a different crater geometry.

Increased turbocharger and aftercooler capacity

Turbocharger and aftercooler capacity have increased to provide increased mass air flow and to handle the cooling requirements of the higher heat loads.

LERV1450

Introduction

Instructor’s Manual

Page 7

Lesson 1 2001

Figure 1-7 3500 Right Side

Right side view: oil filters, fuel filters, fuel hand priming pump, turbochargers, air shutoff, oil pump, oil cooler, fuel transfer pump, water pump

This is the right side view of a 3508 engine. It shows the commercial version with front mounted oil filters (A) and fuel filters (B), fuel hand priming pump (C), rear mounted turbochargers and air cleaners (D), air shutoff (E), oil pump (F), oil cooler (G), fuel transfer pump (H).and water pump (I).

Figure 1-8 3500 Left Side

Left side view: turbochargers, breathers, water regulator housing, oil pan, oil filters, oil level gauge, oil filler pipe, air compressor

This is the left side view of a 3516 vehicular configuration engine. Shown are the top mounted turbochargers (A), crankcase breathers (B), water temperature regulator housing (C), vehicular type oil pan with the sump in front (D), spin-on type oil filters (E), oil level gauge (F), oil filler pipe (G) and air compressor (H).

LERV1450

Introduction

Instructor’s Manual

Page 8

Lesson 1 2001

Figure 1-9 Front view

Front view: water temperature regulator housing, 3161 mechanical governor, manual shutdown lever, water pump, crankshaft extension shaft

This is a front view of a typical 3500 engine. Shown is the water temperature regulator housing (A), 3161 mechanical governor (B), manual shutdown lever (C), water pump (D) and a crankshaft extension shaft (E).

Figure 1-10 Rear view

Rear view: air compressor, accessory drive housing, spin-on fuel filters, flywheel housing adapter ring,

This a rear view of a typical vehicle configuration 3500 engine. Shown is an air compressor (A), accessory drive housing (B), spinon fuel filters (C) and a flywheel housing adapter ring (D).

LERV1450

Introduction

Instructor’s Manual

Page 9

Lesson 1 2001

Figure 1-11 Vehicle Applications

Vehicle applications First 3500 EUI engines

The 3500B engines are commonly used in the larger Caterpillar machines such as the off highway trucks, hydraulic excavators, wheel loaders and tracktype tractors shown here. The Caterpillar vehicle applications were the first to receive engines with the EUI fuel systems.

Figure 1-12 Other Applications

Other applications: Generator sets Marine Industrial

The 3500 and 3500B engines are common in other applications such as electric generator sets, marine vessels, and various industrial installations. Generator sets are used in multiple engine power houses, as individual prime power generators, as auxiliary power units in marine vessels and as standby power supplies. Marine applications include towboats, ferries, tour boats and many others. Industrial engines are used with pumps, compressors, draglines, locomotives and other.

LERV1450

Introduction

Instructor’s Manual

Page 10

Lesson 1 2001

Figure 1-13 Serial Number Plate

Serial number plate: model, serial, arrangement

The serial number plate is located at the left rear on the side of the engine. The plate has the model number, serial number and arrangement number. These numbers are important when ordering parts.

Figure 1-14 Information Plate

Information plate: high idle rpm, full load rpm, full load fuel setting, full torque fuel setting and fuel timing

The information plate is located on the left side of the engine on top of the cylinder block. This plate gives some power rating information such as high idle rpm, full load rpm, full load fuel setting, full torque fuel setting, and fuel timing. Early 3500 engines had the information plate located on a camshaft access cover on the right side of the engine.

LERV1450

Introduction

Instructor’s Manual

Page 11

Lesson 1 2001

Figure 1-15 Auxiliary Drive Shaft

Auxiliary drive shaft: drive cooling fan or generator

Several auxiliary drive shafts are available as options on 3500 engines. They can be used to drive a variety of attachments such as cooling fans and generators.

Figure 1-16 Fan Drive

Fan drive: belt driven vehicle applications

A belt driven fan drive is available and is commonly used in machine applications.

LERV1450

Introduction

Instructor’s Manual

Page 12

Lesson 1 2001

Figure 1-17 Alternator

Alternator: several voltages

A belt driven alternator is available as an option on 3500 engines. Alternators are offered in several voltages and are generally used to maintain battery charge.

Figure 1-18 Air Compressor

Air compressor: gear driven vehicle applications

An air compressor is also available. It is driven off the accessory drive housing and is used in most vehicle applications.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 1

Figure 2-1 Lubrication System and Lube Oils

3500 Lubrication System and Lubricating Oils

Lesson 2 2001

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils

Lesson 2 2001

Page 2

Figure 2-2 3500 Lubrication System

Lubrication System

Oil flow: oil pan, suction bell & screen, oil cooler, oil filters, oil galleries at front

Oil pump pressure relief valve - controls engine oil pressure Oil cooler & oil filter pressure relief valves Oil Cooler differential pressure 180 kPa Oil filter differential pressure 200 kPa - spin-on 287 kPa - commercial

Oil enters engine left front right front some arrangements Oil flow: left camshaft gallery, piston cooling jets through sequence valve - 140 kPa Left camshaft gallery

3500 Engine Lubrication System Lubricating oil is pulled from the oil pan through a suction bell and piping to the oil pump. The suction bell has a screen to provide clean oil to the pump. The pump pushes the oil through the oil cooler and the oil filters and then to the oil galleries in the front of the engine. The oil pump has a pressure relief valve that bypasses excess oil to the pump inlet. This relief valve limits the oil pressure in the engine at startup to 620 - 690 kPa (90-100 psi) with cold oil. The oil cooler and the oil filters have pressure relief valves to limit the pressure drop across the components. The oil pressure relief valve starts to bypass oil around the oil cooler when the difference between the inlet and outlet oil pressure reaches 180 kPa (26 psi). The oil filter bypass(s) start to bypass oil around the oil filter(s) when the pressure differential across the oil filter(s) reaches 200 kPa (29 psi) with the spin-on filters and 287 kPa (42 psi) with the commercial filter. Oil enters the engine block on the left front of the engine on most engines. A few engine arrangements have the oil enter the engine at the right rear and the flow paths change accordingly. For discussion in this material it will be assumed that oil enters at the left front of the engine. At that point, oil flows to the left camshaft oil gallery, the front sequence valve and left side piston cooling jets, and into the main oil gallery. Oil that flows to the left camshaft gallery supplies oil to the left camshaft and lifters and to the valve mechanism in the left cylinder

LERV1450 Instructor’s Manual front sequence valve - left cooling jets 140 kPa (20 psi) Main oil gallery : oil to main bearings, crankshaft and rod bearings Oil at rear to right camshaft gallery, turbochargers, right piston cooling jets

Right camshaft gallery: camshaft bearings, lifters and right valve mechanism Oil flow: piston cooling jets through sequence valve - 140 kPa Oil to other components All oil back to oil pan.

Lubrication System and Lube Oils Page 3

Lesson 2 2001

heads. Oil flowing to the left side piston cooling jets has to first flow through the front sequence valve which prevents oil flow to the piston cooling jets until the oil pressure reaches 140 kPa (20 psi). Oil flowing through the main oil gallery supplies oil to the main bearings which also supplies oil to the connecting rod bearings through drilled ports in the crankshaft. Oil that reaches the end of the main oil gallery at the rear of the engine flows to the right camshaft gallery, the turbochargers, and the right side piston cooling jets. Oil that flows to the right camshaft gallery supplies oil to the right camshaft bearings and lifters and to the valve mechanism in the right cylinder heads. Oil flowing to the piston cooling jets has to first flow through the rear sequence valve which prevents oil flow to the piston cooling jets until the oil pressure reaches 140 kPa (20 psi). Oil is also supplied to the gear trains and mounted components through other drilled passages in the cylinder block. Oil from all the components drains back into the oil pan for reuse.

Figure 2-3 3500 Flow Schematic

Engine lube system schematic

This engine lube system schematic shows: 1. oil pump 2 (lower) oil pump pressure relief valve and oil cooler bypass valve 3. oil cooler 4. oil filters with bypass valve (item 2 upper) 5. main oil gallery 6. piston cooling jet sequence valves 7. camshaft oil gallerys 8. piston cooling jet manifolds 9. turbocharger oil supply lines (vehicular) 10. turbocharger oil drain line

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 4

Lesson 2 2001

Figure 2-4 Vehicle Oil Pan

Vehicle oil pan Front or rear sump

A low volume compact oil pan is available for vehicular and some other applications. The sump can be located in the front or in the rear of the oil pan, depending on the application. This view shows a front sump oil pan.

Figure 2-5 Scavenge Pump, Suction Bell, Screen

Oil scavenge pump

Suction bell & screen Screen can be cleaned

This view shows an oil scavenge pump that can be installed in the vehicular oil pan. Its purpose is to pump the oil out of the shallow end of the pan when the engine is on a steep incline with the shallow end down. This view also shows the suction bell and the suction screen. The screen can be removed and cleaned by first removing the connecting pipe to the oil pump.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 5

Lesson 2 2001

Figure 2-6 Industrial, Genset Oil Pan

Industrial, genset oil pan. Larger capacity and longer oil change periods Marine oil pan deeper with more capacity More oil for rough seas and even longer oil change periods

This view shows an oil pan that is typically used on industrial and generator set engines. The sump extends the full length of the engine and has a much larger capacity than the vehicular oil pan. Industrial and generator sets have a much longer oil change period. This pan can be used on marine engines but marine engines usually have a much deeper oil pan. The deeper pan and larger oil volume is needed to adequately supply oil to the oil pump in rough seas. It also has the added benefit of even longer oil change periods.

Figure 2-7 Oil Pump

Oil Pump: 3 gear pump

Bypass valve 340 to 480 kPa 450 normal at rated

The oil pump is a three gear pump that is driven by the front gear train. A pressure relief or oil bypass valve is in the pump to limit the oil pressure in the engine with cold oil. Normal operating pressures with new filters are between 345 and 480 kPa (50 to 70 psi) with most engines operating at 450 kPa (65 psi) at rated load and speed and with new oil filters.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 6

Lesson 2 2001

Figure 2-8 Oil Pump Bypass

Oil pump bypass valve Returns excess oil back to pump inlet.

The oil pump bypass valve position is controlled by a spring. Both are located in the oil pump housing. The pump limits the oil pressure to 620 - 690 kPa (90-100 psi) by returning excess oil back into the oil pump inlet. This usually will occur at startup while running with cold oil.

Figure 2-9 Oil Cooler

Oil cooler on right side Coolant from water pump Coolant passes to engine

Bypass valve in cooler housing

The oil cooler is a tube core type located on the right side of the engine. The lube oil passes around the tubes to be cooled. Coolant for the oil cooler comes directly from the water pump and passes through the tubes. After passing through the cooler the coolant passes into the engine block to cool the engine. An oil bypass is located in a combination inlet-outlet housing at the front of the oil cooler.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 7

Lesson 2 2001

Figure 2-10 Oil Cooler Bypass Valve

Oil cooler bypass valve

Opens with pressure difference of 180 kPa.

The oil cooler bypass valve is a plunger and spring that is in the oil cooler housing. It permits oil to go around the cooler when the oil is cold and thick or when there is a restriction in the cooler. The bypass will open when there is a pressure difference between the inlet and outlet of about 180 kPa (26 psi).

Figure 2-11 Spin-on Oil filters

Spin-on oil filters 2 to 4 assemblies

Oil filter bypass Opens 200 kPa

Spin-on type oil filters are standard on vehicle engines and are an option on engines used in other applications. The individual full flow filter assemblies are bolted together in groups of 2 to 4 depending on the engine size. Each oil filter has a bypass valve located behind the plates (see arrows) that permits oil flow around the filters if there is a restriction from plugging, cold oil or from rapid startup flow into an empty filter. Each valve will open when there is a pressure difference across the filter of about 200 kPa (29 psi).

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 8

Lesson 2 2001

Figure 2-12 Spin-on Oil Filter

Spin-on filter elements Common industry use Caterpillar filters for longest filter and engine life

The spin-on filter elements are an industry standard size that is used by other engine manufacturers on many sizes of engines. Aftermarket filter elements are available from many suppliers but for the longest filter and engine life and the best filtering capabilities only the Caterpillar filters should be used in 3500 engines.

Figure 2-13 Front Mounted Oil Filters

Front mounted oil filter housing. 3 replaceable elements Bypass valve Left or right side servicing

This is a commercial front mounted oil filter unit commonly used in marine, generator set and industrial applications. The filter housing has three replaceable cartridge elements. The filter housing has a bypass valve that permits oil flow around the filters if there is a restriction from plugging, cold oil or from rapid startup flow into an empty filter. The front mounted filters can be set up for either left or right side servicing. This one is set up for left side servicing.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 9

Lesson 2 2001

Figure 2-14 Duplex Oil Filters

Duplex oil filter: regular filter changeover valve reserve filter

Short service time

Bypass valve

This view shows a duplex front mounted oil filter. It is the regular front mounted filter but with a changeover valve and a reserve filter added. When the changeover valve is moved to the service position with the engine running, the engine oil flows through the reserve filter so the main oil filters can be changed. Operation with the reserve filter should only be for a short time. A bypass valve has also been included in the duplex oil filter housing.

Figure 2-15 Oil Filter Bypass Valve

Bypass valve 287 kPa open

All the front mounted oil filters use the same front mounted bypass valve. The valve is set to open at about 287 kPa (42 psi).

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 10

Lesson 2 2001

Figure 2-16 Oil Supply Elbow

Main oil supply to engine left front: camshaft bearings main oil gallery sequence valve and piston cooling jets turbocharger lubrication

The main engine oil supply enters most of the 3500 engines at the left front of the engine through the oil supply elbow shown. The right port in the cylinder block pipes oil to the left camshaft bearings. The left port supplies oil to the main oil gallery, the front piston cooling jet sequence valve and the left piston cooling jets. Provision has also been made to provide oil to top mounted turbochargers and other accessories.

Figure 2-17 Lube Oil Adapter Block

Adapter block: connects main oil gallery with camshaft oil supply rear turbo oil supply Rear PCJ sequence valve and right piston cooling jets Oil supply at this location

The lube oil adapter block which is located at the right rear of the cylinder block on most 3500 engines connects the main oil gallery with the right side camshaft bearing oil supply gallery. Provision is also made to supply oil to rear mounted turbochargers. Oil is supplied to the rear piston cooling jet sequence valve and right side piston cooling jets at the rear of the main oil gallery. Some engines have been produced with the main oil supply entering at this location. On those engines the lube oil adapter block shown here is located on the left front of the engine block.

LERV1450 Instructor’s Manual

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Lesson 2 2001

Figure 2-18 Piston Cooling Jet

Piston cooling jet installation Precise positioning

Older cast iron jet shown new fabricated jets now used

The piston cooling jet (A) extends through the oil manifold (B) in the cylinder block and is locked in place by a retainer (C). A slot in the jet and a close fitting tab on the retainer precisely position the jet in the cylinder block. This view shows the older style piston cooling jet. The newer jets are fabricated from steel and tubing but they function the same as the cast iron jets.

Figure 2-19 PCJ Spray Orifices

Piston cooling jet orifices: A - oil into passageway past pin and into cooling gallery B - oil onto bottom of piston cools piston lubricates piston pin

This is a view of the piston cooling jet orifices as seen looking down the cylinder liner. There are two orifices. Orifice A sprays oil into a passageway in the skirt of the piston. Oil passes upward past the piston pin and into the cooling oil gallery in the top of the piston. Oil from orifice B sprays oil up into the bottom of the piston to cool the skirt of the piston and to provide lubrication to the piston pin.

LERV1450 Instructor’s Manual

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Lesson 2 2001

Figure 2-20 PCJ Sequence Valve

PCJ sequence valve valve and spring two bolt cover

No oil to PCJ until pressure reaches 130 kPa to lubricate engine quicker

The piston cooling jet sequence valves are located in the front and rear of the cylinder block. The valve shown is installed in the hole with the spring to the outside. A two bolt cover retains the valve and spring. The sequence valve keeps oil from the piston cooling jets until the oil pressure reaches about 140 kPa (20 psi) so lube oil can build up oil pressure and reach all parts of the engine much quicker.

Figure 2-21 Prelubrication

3500 prelubrication systems electric and air operated marine, genset, and industrial prelube not required

Some 3500 engine customers desire or require prelubrication systems on their engines. Both electric and air operated engine mounted prelubrication systems are available as options. Prelubrication systems are primarily seen in marine and some generator set and industrial applications. Prelubrication is not required for any 3500 applications but it offers the potential for reducing startup wear.

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Lesson 2 2001

Figure 2-22 Lubricating Oil

Lubricating oil

The following section will discuss briefly lubricating oil, 3500 engine lubricating oil requirements and oil change options for 3500 engines.

Figure 2-23 Lube Oil Functions

Lubricating oil: lubricate friction surfaces cool engine parts flush combustion particles prevent rust and corrosion neutralize harmful acids

Lubricating oils serve several vital functions in the engine: 1. Lubricate friction surfaces by forming a fluid film to minimize metal to metal contact 2. Cool the engine parts and carry away nearly one-third of the engine heat from the engine components at full load 3. Clean the engine by flushing away dirt and wear particles 4. Reduce rust and corrosion inside the crankcase - water is a product of combustion, water vapors are always present inside the crankcase and oil coats all the internal surfaces. 5. Protect the engine from harmful acids and deposits formed from the products of combustion - additives in the lube oil can neutralize the harmful acids

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Lesson 2 2001

Figure 2-24 History

First lube oil for Cat diesels: mineral oil

Better oil needed

1935 first additive oil: Superior Lubricants for Caterpillar Engines

Performance standards from tests on single cylinder test engine

Test run, deposits and wear measured

1940’s extensive testing with oil industry

New performance levels established

Lubricating oil used in reciprocating engines in 1931 was a straight mineral crankcase oil. When the first Caterpillar diesel engines were introduced that year, they began experiencing ring sticking, cylinder liner scratching and high component wear. Test results indicated that a more effective oil was needed. In 1935 the first additive crankcase oil was developed in a cooperative effort between several western U. S. oil companies and Caterpillar. This crankcase oil was called “Superior Lubricants for Caterpillar Engines” and was initially sold only by Caterpillar Dealers. Other oil companies soon came on the market with similar oils. The performance standards for this and subsequent oils were established by tests run on a single cylinder test engine designed and manufactured by Caterpillar. These same types of tests and engines are still being used today. The test engine was run for a designated time at a predetermined load and speed with the test oil in the crankcase. The engine was then disassembled and the special test piston was inspected. The color change caused by lacquering was observed and recorded. Other critical factors such as ring wear and deposits were measured. In the 1940's, Caterpillar began an extensive testing program in cooperation with the oil industry. The program included both laboratory and field testing. The studies pointed out the damaging effects of fuel impurities and the heavy deposits formed in high output engine cylinders. New performance levels for lubricating oils were established.

LERV1450 Instructor’s Manual

More oil improvements, new additive package

Superior Lubricants Series 2 recommended for Cat Engines

Lubrication System and Lube Oils Page 15

Lesson 2 2001

Fuel with higher sulfur content became common during the mid 40's. This, along with the higher output engines, brought about the need for more lube oil improvements. Pooled efforts by Caterpillar and the major oil companies brought about a new additive package that resulted in new oils that were named “Superior Lubricants Series 2”. Caterpillar recommended exclusive use of these oils in Caterpillars’ Engines.

1947 - API Classification system Regular, Premium, Heavy Duty

In 1947 the American Petroleum Institute (API) introduced an oil classification system which categorized the existing oils into 3 types based on engine service: regular, premium and heavy duty.

1956 - Series 3 required in Cat turbocharged engines

In 1956, further lube oil improvements established the Series 3 classification. Caterpillar required the use of Series 3 oils in Caterpillar turbocharged engines.

1970 - classification system revised

In 1970, the API, American Society for Testing and Materials (ASTM) and the Society of Automotive Engineers (SAE) revised the classification system. Their new system was based on the same type of performance specifications which Caterpillar and others had been using.

Cat dropped testing & classifying, supplied test engines to test labs

Caterpillar dropped its classification system in 1972 but supplied the industry standard, single cylinder test engines to the oil companies and independent testing labs for future oil testing.

New API performance category classifications

The new API system established letter designations for oil performance category classifications. These refer to performance levels in engine tests. The “C” designated oils are commercial oils (diesel). The “S” designated oils are for automotive use (gasoline engine).

C - Diesel engines S - gasoline engines

CD oils satisfactory for Cat engines in 1970

API CD oils were the best quality oils available with the new classification system. All Caterpillar diesel engines could operate with any CD oil satisfactorily and continued to do so for many years to come.

High ratings & reduced emissions

In recent years lube oils have had to be further improved to perform satisfactorily in the newer diesel engines. Higher ratings and reduced emissions have caused higher piston and ring temperatures. CF-4, CG-4 and most recently CH-4 oils were developed to address these needs. The CD performance category oil has most recently been upgraded to CF. Oil classifications will be further upgraded in the coming years as engine demands continue to increase.

Higher piston temperatures CH-4 required CD upgraded to CG More upgrades coming

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Lesson 2 2001

Figure 2-25 3500 Lube Oils

CD oils - 1970”s CF-4 oil for 3500 engines 1992 CF-4 higher piston temperatures 2 piece pistons higher top ring higher soot levels lower fuel consumption reduced emissions CF-4 available 1990 Improved to CG-4 then CH-4

Starting in the early 1970’s Caterpillar diesel engines were designed to operate on any CD performance category oil. In 1992 it was recommended that only CF-4 engine oils be used in 3500 engines. The CF-4 oils were developed to tolerate the higher piston and ring temperatures occurring because of ever rising horsepower ratings and the higher piston crown temperatures seen with the newer two piece pistons having higher top ring positions. The oils could handle higher soot levels without increasing piston deposits. The piston changes also came about because of the need for lower fuel consumption and reduced emissions. Since the CF-4 oils became available in 1990, the oils have been improved and the designations changed, first to CG-4 and then to CH-4.

Caterpillar Diesel Engine Oil preferred for 3500 diesel engines 10W-30 & 15W-40

Caterpillar Diesel Engine Oil is the preferred engine oil for 3500 diesel engines. It comes in SAE 10W-30 and 15W-40 viscosities. Both are approved by Caterpillar for 3500 diesel engine service.

Commercial engine Oils: API CH-4 designation

If commercial engine oils are used the oil must carry an API CH-4 designation. In some locations, if CH-4 is not yet available, the older CG-4 designated oil may be used.

SAE 10W-30 or 15W-40 preferred Lower viscosities in cold start applications

The preferred commercial oil viscosities are SAE 10W-30 and 15W40, especially in constantly running engines. For intermittent applications where cold starts are frequent, select the highest viscosity oil that is acceptable to meet the startup temperature requirements.

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Lesson 2 2001

Figure 2-26 Oil Change Periods

Change period: hours or oil analysis Change by hours most common Desirable to get as much life as possible

Hours - O & M Manuals 250 vehicular 500 shallow pan 1000 deep pan

S•O•S trend analysis condemning limits 3 or more used oil samples

Extended oil change new oil sample baseline sample 2 or more used oil samples - 250 hr. maximum recommended oil change period sample

The oil change period can be determined two ways: a set number of hours or by lube oil analysis. Changing the oil and oil filters based on a set number of hours has been the most common practice in the past but from an environmental and cost standpoint, it is desirable to get as much life from the oil as possible. Extended oil change periods may be possible when regular S•O•S oil analysis is used. If the oil must be changed based on a set number of hours or if S•O•S oil analysis is not available for an engine, then the oil change period is conservatively set at the hours shown in the appropriate Operation and Maintenance Manuals for the engine. Typically, oil and oil filter change periods have been 250 hours for vehicular engines with the small oil pan, 500 hours for industrial, marine, and generator set engines with the shallow pan and 1000 hours for engines with the deep pan. To give the engine the best protection possible and still get as much life as possible from the engine oil, S•O•S oil analysis must be used. Oil change intervals are based on trend analysis' of the oil sample results and the condemning limits established for the engine. At least three used oil samples are needed. The following samples are required for extended oil changes. 1. A new oil sample is needed by the oil lab to be used as a test reference. 2. A baseline sample should be taken shortly after the engine has been started and warmed up following an oil change to show any wear metal carryover from the previous oil. 3. Two or more oil samples should be taken before the recommended oil change interval and with the larger oil sumps, the sample periods should not exceed 250 hours. 4. An oil sample should be taken at the recommended oil change interval.

LERV1450 Instructor’s Manual sample every 50 hr. until maximum hr. established

Use cautious approach several oil changes at recommended hr. several changes at recommended plus 50 hr. several changes at recommended plus 100 hr. Oil change periods reduced over time

Lubrication System and Lube Oils Page 18

Lesson 2 2001

After the recommended oil change period oil sample, oil samples should be taken and analyzed every 50 engine hours until the maximum established period has been reached. A cautious approach should be used in determining an extended oil change period. First, make several oil changes at the recommended service interval. If analysis’ shows the oil condition to be satisfactory, extend the period by 50 hours and stay at that change interval for several changes. Increase the interval another 50 hours if the analysis is good. The change periods will probably be reduced over time as the engine gets more accumulated hours.

Figure 2-27 Oil Analysis - Wear

Oil analysis results: wear analysis oil condition oil contamination Wear analysis: trend lines established limits

Increase - impending failure

Increase - additives depleted trend analysis necessary

Analysis' performed on oil samples requires three test procedures: wear analysis, oil condition analysis and oil contamination analysis. Wear analysis—The S•O•S program has established guidelines for all appropriate wear elements based on the standard drain period. These wear tables indicate general levels of wear materials in average conditions. Trending is an essential part of Wear Rate Analysis. After three samples have been taken from an engine, a trend for each wear metal is established. Interpreters then compare subsequent samples to this trend line to quickly spot deviations as well as monitor gradual changes in concentration levels. • A large increase in one or more of the wear elements can indicate a problem area which may indicate an impending failure. This has been the primary use of wear analysis in the past. • Wear elements will show an abnormal increase when some of the lube oil additives are nearly depleted. These values are much lower so trend analysis of regular oil sample results is necessary.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 19

Lesson 2 2001

Figure 2-28 Oil Analysis - Oil condition

Oil condition & contamination

Oil condition and contamination -- Infrared analysis is now used to monitor soot, oxidation and sulfur products. Other tests measure water and glycol content, fuel dilution, TBN and any change in oil viscosity. These are the guidelines for each:

Infrared analysis: soot products oxidation sulfur

• Soot Products and Oxidation are 100% of Caterpillar established program values • Sulfur Products indicate an unfavorable oil condition trend • Water content is more than 0.5% • Glycol is present • Fuel dilution is greater than 4% • TBN is 50% or less that of new oil • Oil viscosity change is more than +/-3 cSt when compared with new oil at 100° C

Water Glycol Fuel dilution TBN Oil viscosity change

New oil sample Results: comparison of used and new oil

Lube oil labs require a sample of unused oil, of the lube oil being analyzed, to make an accurate evaluation of the used oil condition. Infrared Analysis results, wear materials, TBN and viscosity change are all based on the changes seen in the analysis compared to new oil. It is a good idea to submit a sample of unused oil periodically. Some labs suggest sending an unused sample along with the first used sample after each oil change.

LERV1450 Instructor’s Manual

Lubrication System and Lube Oils Page 20

Lesson 2 2001

Figure 2-29 Oil Sample Kit

Sampling kit for “live” oil sample 169-8373 kit: includes sample bottle and cap, sample probe Mailing containers, sample valves, adapters available

Purchase from Cat dealer with mailing label S•O•S can be included

A sampling “kit” is available that can take a “live” oil sample when the engine is running. This live oil sampling kit makes it easy to obtain an oil sample with less chance of contamination. The 169-8373 sampling “kit” includes a bottle with a disposable sample probe and a cap. A mailing container with a label can also be obtained. Sample valves or adapters with a rubber dirt cover are available for permanent installation on the engine. These sampling kits, valves and mailing containers can be purchased from a Caterpillar dealer and may have pre-addressed mailing labels for easy S•O•S processing. Processing can also be included in the purchase price if desired.

Sample valve in pressurized oil line

The sample valve should be placed in a pressurized oil line (main oil manifold preferred) where the oil is actively flowing.

Take oil sample: engine hot purge sample valve

Before taking an oil sample, operate the engine until it is at the normal operating temperature. Take a small amount of oil from the sample valve with an old sample probe to purge any dirt from the valve and to bring fresh oil into the valve.

insert probe fill bottle to marker remove probe cap bottle

Insert the probe of a new sample bottle into the adapter and fill it to the marker on the bottle. Remove the probe from the sample valve, remove and discard the sample probe from the bottle, and press the cap securely on to the top of the bottle.

fill out labels send to dealer for analysis

Fill out the sample and shipping labels and send the sample container to your Caterpillar Dealer for the S•O•S analysis. Make sure the engine serial number, engine hours, hours on the oil and oil brand designation are indicated. An oil sample without the requested information on the sample label has little value.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 1

Figure 3-1 Intake and Exhaust System

Air Intake and Exhaust System

Lesson 3 2001

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 2

Lesson 3 2001

Figure 3-2 3500 Air & Exhaust Flow

Air & exhaust flow - older 3500 engines turbocharger aftercooler housing aftercooler inlet elbow intake valve & cylinder exhaust valve exhaust manifold turbocharger

This schematic shows the air and exhaust flow in the older 3500 engines. Air flows into the turbocharger compressor, into the aftercooler housing, through the aftercooler core, and into the air plenum or intake manifold. Combustion air then flows through connecting elbows to the cylinder heads, intake valves, and into the combustion chamber. Exhaust in the combustion chamber flows out through the exhaust valves, into the exhaust manifold and into the turbocharger turbine to drive the turbocharger.

Figure 3-3 3500 Air & Exhaust Flow - B Series

Aftercooler above engine Cylinder block air plenum not used Air flows directly into head Higher capacity, more efficient

The aftercooler sits up above the engine cylinder block on the B series engines. The intake plenum in the cylinder block is not used. After the air passes through the aftercooler core, it flows directly into the cylinder heads through a more direct path. This aftercooler is not only higher capacity but it gives much more efficient air flow because of the more direct air flow path.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 3

Lesson 3 2001

Figure 3-4 Aftercooler Core

Aftercooler core - older engines Air flow through core into inlet manifold plenum out through ports to elbows and into heads B Series mounted above engine in housing - air manifold plenum not used

Item A shows the aftercooler core mounted on the cylinder block of an older 3500 engine. Air flows through the aftercooler core and into the cylinder block inlet manifold plenum. From the inlet manifold air plenum, air flows out the ports (B) and into the elbows that deliver the combustion air to the cylinder heads. The B series and Phase II aftercooler cores are similar but are completely mounted in a housing that sits above the engine block. Air passes more directly into the cylinder heads and the air plenum in the cylinder block is covered and not used. Ref. Figure 3-3.

Figure 3-5 Air Shutoff

Air shutoff - older style flapper valve trip solenoid manual reset knob flapper assist Closes overspeed manual emergency shutdown

Engines with the rear mounted turbochargers have an air shutoff (A) option. The shutoff in this view is typical of the older 3500 engines. A flapper valve inside the shutoff is held in the open position by the plunger of the trip solenoid (B). When the trip solenoid is activated the flapper valve moves across the shutoff housing to block off the air flow to the engine. A manual reset knob (C) resets the shutoff after it has been tripped. Item D is a spring and plunger that assists the flapper valve to close. The air shutoff only closes if an engine overspeed occurs or if the emergency shutoff is manually activated.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 4

Lesson 3 2001

Figure 3-6 Air Shutoff

B Series shutoffs - in air pipes spring loaded butterfly an activation cylinder or a solenoid reset knob Trip only on overspeed or manual emergency shutdown

The B series engines with rear mounted turbos also have air shutoffs (A). This arrangement has a shutoff in both air pipes coming from the turbochargers. These shutoffs have a spring loaded butterfly valve that is held open by the activation cylinder (B) or a solenoid. The activation cylinder or the solenoid allows the butterfly to close when tripped. A manual reset knob (C) resets the shutoff. In the event of an overspeed or a manual emergency shutdown both air shutoffs are closed.

Figure 3-7 Exhaust Manifolds

Exhaust manifolds - hot Water-cooled/shielded available as option

This view shows the exhaust manifolds on an older 3500 engine. These manifolds are uninsulated. Water-cooled and shielded manifolds are available as an option.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 5

Lesson 3 2001

Figure 3-8 Rear Mounted Turbos

Rear view turbos exhaust couplings exhaust collector air cleaner

This is a rear view of a 3500 engine with rear mounted turbochargers. Shown are the turbochargers (A), exhaust couplings (B), the exhaust collector from both turbochargers (C) and an engine mounted aircleaner (D).

Figure 3-9 Camshaft

2 camshaft assemblies each side 3508 one piece 3512, 3516 two piece Bearing journals Exhaust lobe Intake Lobe Injector lobe B cams 6 mm larger drive high pressure injectors

All 3500 engines have two camshaft assemblies, one on each side. The 3508 camshafts are a single piece assembly, the 3512 and 3516 camshaft assemblies are two sections bolted together in the center. Items A shown above are bearing journals which are located between each cylinder. Item B is an exhaust valve cam lobe, item C is an intake valve lobe and item D is a fuel injector cam lobe. The fuel injector camshaft lobe (and lifter) is wider than the valves on the B series because of the higher load on the camshaft lobe. The camshafts on the B series engines are also 6 mm larger in diameter than previous 3500 engines to be able to drive more aggressively the high pressure injectors.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 6

Lesson 3 2001

Figure 3-10 Camshaft Bearings

Camshaft bearings in block Oil holes and bearing joint installed correctly

This view shows the camshaft bearings installed in the cylinder block. The bearings must be installed with the oil holes and bearing joint located a certain way in the cylinder block to give maximum service life. Refer to the service manual for the details.

Figure 3-11 Camshaft Bearings

Camshaft bearings Groove in circumference lubricate camshaft oil to lifters & valve mechanism

These are camshaft bearings. Note the grooves machined around the outer circumference of the bearings. Oil coming from the camshaft oil gallery flows to the area with the groove. Oil flows to the camshafts through the oil holes in the bearing and also around the groove and out a drilled port in the cylinder block. This port supplies lube oil to the lifter and valve mechanism in the cylinder head.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 7

Lesson 3 2001

Figure 3-12 Camshaft Bearing Tools

Camshaft bearing tooling Hydraulic equipment can be used

Tooling is available to remove and replace camshaft bearings in 3500 engines. This tooling can be used with standard hydraulic equipment to make the job easier and faster. Refer to the service manual for the proper use of this tooling.

Figure 3-13 Camshaft Installation Tools

Camshaft installation tooling guide pilots handle to rotate camshaft

Tooling necessary to prevent bearing damage

This tooling should be used to remove and install the camshafts in 3500 engines. Item A is a guide that correctly aligns the camshaft with the bearing, and it can be used for either front or rear camshaft removal and installation. Items B are pilots that bolt on to both ends of the camshaft to support the camshaft as it passes through the engine. Item C is a handle that is bolted to the end of the camshaft or pilot to rotate the camshaft as it is removed or installed. Rotating the camshaft as it is being moved in the engine makes removal and installation much easier. Use of this tooling is necessary to prevent damage to the camshaft bearings. Refer to the service manual for details.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 8

Lesson 3 2001

Figure 3-14 Install Camshaft

Camshaft installed from rear Tooling shown Two piece camshaft as unit or separately

This view shows a camshaft being installed from the rear of the engine. Guide A, Pilot B and handle C are shown here in use. The camshaft shown is a two piece camshaft that has been preassemble and will be installed in the engine as a unit. Where adequate space is not available to do this, one piece can be inserted nearly into the engine, the second piece assembled to the installed piece then the whole camshaft inserted into the engine. Refer to the service manual and parts book to determine correct part location and orientation.

Figure 3-15 Camshaft Gear

Camshaft drive gear Camshaft timed to crankshaft when gear installed

The camshaft drive gear mounts to the camshaft at a tapered joint and is held in place by a single bolt. This joint is not keyed or splined so the camshaft must be timed to the crankshaft when the gear is installed.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 9

Lesson 3 2001

Figure 3-16 Camshaft Gear Puller

Gear forced on to shaft Remove with puller Do not heat gear

The camshaft gear is forced very firmly onto the tapered end of the camshaft. The best way to remove the gear is with the puller shown. Avoid heating the gear to ease removal as the gear will have to be replaced if the gear is heated.

Figure 3-17 Remove Cam Gear

Remove cam gear

Once the gear has been loosened from the end of the shaft, the gear can be easily removed through the access in the flywheel housing at the rear of the camshaft.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 10

Lesson 3 2001

Figure 3-18 Gear Installation

Install gear onto camshaft torque bolt drive gear or hit bolt retorque bolt repeat hit/torque procedure until seated

When installing the gear on to the tapered camshaft end, the bolt is torqued then the gear tapped with a driver as shown or the end of the bolt tapped with a brass hammer to help seat the gear on to the shaft. Retorque the bolt and repeat the hit and retorque procedure until the bolt no longer turns when retorqued.

Figure 3-19 Camshaft Timing Pin

Time the camshafts insert pins in slots pins stored under rear covers

Do not rotate crankshaft after gear is installed

To time the camshafts to the engine crankshaft, first rotate the camshaft until the camshaft timing pin can be inserted into the slot in the camshaft. The timing pins are stored under the rear camshaft access covers on both sides. Note: Do not rotate the crankshaft with the camshaft timing pins in place after the cam gears have been installed. The pins and possibly the camshafts will be damaged.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 11

Lesson 3 2001

Figure 3-20 Flywheel Timing Pin

Rotate crankshaft Insert timing bolt through flywheel housing and thread into flywheel

After the camshafts have been pinned, rotate the crankshaft in the direction of normal rotation with the turning tool until the timing bolt can be inserted and threaded into the hole provided in the flywheel housing and flywheel. This sets the engine crankshaft at top center number 1 cylinder.

Install gear

Install the camshaft drive gear as described in the service manual.

Do not rotate crankshaft with pins in place Remove pins

Note: Do not rotate the crankshaft with the timing bolt in place as damage to the bolt and flywheel will be certain. It is recommended that the flywheel and camshaft timing pins be removed after the camshaft gear retaining bolt has been lightly tightened.

LERV1450 Instructor’s Manual

Air Intake and Exhaust System Page 12

Lesson 3 2001

Figure 3-21 Rear Gear Train

Rear gear train crankshaft gear cluster gear camshaft idler gears camshaft drive gears timing ring balancer/cluster gear on 3508 engines - timed to crankshaft gear

This view shows the rear gear train which includes a crankshaft gear, a cluster gear which reduces the camshaft speed by 50%, two camshaft idler gears and the two camshaft drive gears. B series engines also have a timing ring on the left camshaft drive gear which provides a speed and timing signal to the electronic engine control. On 3508 engines the cluster gear is weighted and acts as a balancer. The balancer cluster gear must be timed to the crankshaft gear.

Figure 3-22 3508 Balancer Gear

Balancer gear on front of engine Timed to crankshaft gear timing marks on the gears

The 3508 engines have a balancer gear on the front of the engine as well as the rear. This gear must be properly timed to the crankshaft. There are timing marks on the balancer gear and the crankshaft gear.

LERV1450 Instructor’s Manual

Cylinder Head Page 1

Figure 4-1 Cylinder Head

Cylinder Head

Lesson 4 2001

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 2

Figure 4-2 Cylinder Head

3500 Cylinder Head serviced separately stress relieved gray iron

This is a drawing of a 3500 engine cylinder head. Each cylinder has its own head and can be serviced separately of the other cylinders. The head castings are formed from stress relieved gray iron.

Figure 4-3 Threaded Valve Guide

Valve guide knurled close fit good lubrication long life effective seal

This is a valve guide installed in a 3500 cylinder head. The inside diameter of all valve guides are knurled. The knurl in the valve guide gives a close fit and at the same time provides lubrication for long life and an effective seal.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 3

Figure 4-4 Valve Seat Insert &Tool

Replaceable valve seat inserts Removal & installation tool

The 3500 engine cylinder heads have replaceable valve seat inserts. This view shows a slide hammer removal and installation tool. There is an insert on the tool.

Figure 4-5 Valve Components

Valve components valve two springs washer seat rotator locks Valve springs same all valves B series more powerful springs Rotators & locks same all valves

This view shows the valve components. They include a valve, two valve springs, a washer (spring seat), a valve rotator and two locks. Inlet and exhaust valves were the same in all 3500 engines through the early B series engines. Valve seat angles were 30 degrees on all valves. Later B series engines had the same dimensions but had a 20 degree inlet valve angle and a 45 degree exhaust valve angle. The valve springs are the same on all valves. The smaller spring is installed inside the larger spring. B Series and high displacement engines have more powerful springs. The valve rotators and locks have been the same on all valves.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 4

Figure 4-6 Valve Springs

Valve springs on spring guide smaller spring inside larger spring

The valve springs are positioned on the top of the head deck by a washer or spring guide. The smaller spring is installed inside the larger spring.

Figure 4-7 Rotators & Locks

Valve rotator on spring Locks retain rotator

The valve rotator is installed on top of the valve springs and two locks retain the rotator in place.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 5

Figure 4-8 Valves & Injector

Cylinder head: 8 bolts exhaust springs & rotators intake springs & rotators bridges mechanical unit injector injector rack lever exhaust valve lifter intake valve lifter injector lifter

The cylinder head is installed to the engine with eight bolts (A). The bolts are liberally coated with engine oil before installing then torqued according to the service manual. Also shown are the exhaust valve springs and rotators (B), intake valve springs and rotators (C), valve bridges (D), mechanical unit injector (E), injector rack lever (F), exhaust valve lifter (G), intake valve lifter (H) and injector lifter (I).

Figure 4-9 Head with Valves & Lifters

Cylinder head bottom deck valves injector lifters - all same size B series injector lifter width increased Valve lifter size reduced

This shows the bottom deck of an early model 3500 engine cylinder head with the valves and fuel injector installed. Shown also are the valve and injector lifters. These lifters are all the same size. B series engines increased the width of the injector lifter and roller to give it added strength for the higher loads it would experience. The valve lifters were reduced in size accordingly.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 6

Figure 4-10 B Series Camshaft & Lifters

Wider injector cam lobes & lifter higher lift 20% higher injection pressure

Valve cam lobes & lifter narrower

The B Series engines have wider injector camshaft lobes and lifter rollers than previous 3500 engines. The wider lobe and lifter were needed because of the higher loading of the camshaft lobe and lifter. The lift has been increased to give 20% higher injection pressure. The valve camshaft lobes and lifters are narrower to accommodate the wider injector lifters.

Figure 4-11 Lifter & Spring

Roller follower lifter Guide spring prevent wobble retain lifter in head Lifters all the same - older engines Different on B series

The valve and injector lifters are a roller follower type lifter. They have a guide spring that snaps around the body of the lifter with the tab on the spring riding in the guide slot on the lifter. The spring guide prevents lifter wobble on the lobes and retains the lifter in the cylinder head when the head is removed or installed. The same lifter is used for both the valves and injector on all engines up to the B series. The B series engines have a wider injector lifter and narrower valve lifters. Note: The guide springs must be replaced if they have been removed form the lifter.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 7

Figure 4-12 B Series Valve Mechanism

B series valve components changed Injector lifter, pushrod, rocker arm strengthened Pushrod has helper spring

Electronic unit injectors

B series valve train components have been changed from the earlier engines. The width of the lifters has been changed and the valve seat angles have changed on later B series engines. Bridges and valve rocker arms have not changed much except the lifter is shorter and the pushrods are longer and smaller diameter. The injector lifter, pushrod and rocker arm have been strengthened considerably. The B series injector pushrod has a helper spring to keep the camshaft follower in constant contact with the camshaft and the B series engines have electronic unit injectors.

Figure 4-13 Install Spacer Plate

Thin metal spacer plate gasket Silicone bead Spacer plate Positioned by oil feed tube & 2 dowels

A thin metal spacer plate gasket is installed between the spacer plate and the cylinder block. The gasket has a fine preapplied silicone gasket bead on the side and across the bottom of both sides of the gasket to seal oil inside the engine. The aluminum spacer plate is installed on the gasket and they both are positioned on the block by an oil feed tube on the pushrod end and two dowels above the cylinder bore.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 8

Figure 4-14 Water Ferrules

Eight ferrules flow water Two sizes

Eight ferrules are installed in the spacer plate to flow the coolant from the cylinder block into the cylinder head. Two different size ferrules are used.

Figure 4-15 Head Gasket

Head gasket silicone bead fire ring 2 locating dowels oil feed tube o-ring seals

This view shows the cylinder head gasket installed. It has a fire ring that seats on the top of the cylinder liner. The most recent gasket has a silicone bead around the lifter area and has tape to hold the loose fitting fire ring in place on the new gasket. The tape is not removed during assembly. Shown also are the two locating dowels and the oil feed tube. An o-ring seal is placed above and below the spacer plate.

LERV1450 Instructor’s Manual

Cylinder Head

Lesson 4 2001

Page 9

Figure 4-16 Inlet Elbows

Inlet elbows combustion air from vee to heads High mounted aftercoolers low restriction connecting pipes

All 3500 engines prior to the B series and Phase II engines with the high mounted aftercoolers had inlet air elbows that flowed the combustion air from the inlet manifold in the vee of the engine to the cylinder heads. B series engines and Phase II engines with the high mounted aftercoolers do not use the elbows but pass the air directly from the aftercooler housing to the cylinder head through low restriction connecting pipes.

Figure 4-17 Rocker Arm Bases

B series rocker base wire channel electrical connector spring boss constant lifter contact with camshaft reduce cam failure steel inserts

B series engine rocker bases have added a machined channel to route the fuel injector wiring to a hole and connector in the side of the rocker base. A helper spring boss has been added to hold a spring assist pushrod that maintains a constant pressure on the injector lifter to keep it in constant contact with the camshaft. This reduces the risk of camshaft damage or failure. Steel inserts for the rocker arm support have also been added for added strength in that area.

LERV1450

Pistons, Rings & Liners

Instructor’s Manual

Page 1

Figure 5-1 Pistons, Rings and Liners

Pistons, Rings and Liners

Lesson 5 2001

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 2

Lesson 5 2001

Figure 5-2 Connecting Rod

Forged steel rod taper pin bore end more material in the piston greater rod strength Rod cap over sides with 4 angled bolts maximum strength larger bearing narrow rod Bushing proof test to 30 kN

The connecting rod is forged steel with a taper on the pin bore end. This allows more material in the piston to give it added strength while still giving more strength in the high load area of the rod. The rod cap installs over the sides of the large end of the rod and is retained with 4 angled bolts. This design gives maximum strength to the rod, a larger size connecting rod bearing and a rod narrow enough to be removed thorough the cylinder liner. The rod eye bushing has a very tight press fit. At each overhaul, if the rod is to be reused, the rod eye bushing should be proof tested to be sure that there is no movement when a force of 30 kN (6750 lbs) is applied to the bushing.

Figure 5-3 Connecting Rod Chamfer

Two con rods side by side one side chamfer clearance to crank radius one side flat next to other rod

Two connecting rods are installed side by side on the same crankshaft journal. One side of the connecting rod has a chamfer on the large end bore. That side is installed against the crankshaft cheek. The chamfer gives clearance for the rod with the fillet radius of the crankshaft. The other side of the rod does not have a chamfer. It goes against the flat side of the other rod on the journal.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 3

Lesson 5 2001

Figure 5-4 Connecting Rods

Two rods the same Flat sides together

This shows two connecting rods as they would be installed in an engine. The left and right rods are the same but the flat sides of both run together as shown.

Figure 5-5 Rod & Bearings

Rod & cap bearings installed bearing halves identical tabs fit snugly in slot tabs on same side but offset dowel in cap slot in rod

This shows the connecting rod and cap with the bearings installed. The top and bottom half of the bearings are the same. The bearings are located in the bearing bore by the bearing tabs which fit snugly in the tab slots in the rod and cap. When the cap is installed the tabs will be on the same side but will be offset. The cap can only be installed one way because there is a locating dowel or pin on one side of the cap and a locating slot on only one side of the connecting rod.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 4

Lesson 5 2001

Figure 5-6 Assemble Connecting Rod

Connecting rod cap installed one way only cover sides of rod angled bolts added strength of big end

The connecting rod cap can only be installed on the rod one way because of the locating slot and locating dowel. This view also shows the connecting rod cap as it will cover the narrow connecting rod sides, and the location of the angled bolts, all which give the rod big end added strength.

Figure 5-7 Tighten Con Rod Bolts

Connecting rod bolts tightened in sequence 1 & 2 on bearing tab and locating dowel side

Clean bolts, coat with Molykote Keep Molykote off all other mating surfaces

The connecting rod bolts are tightened in a certain sequence so that the bolts all have the same stretch (tightness) and the bearing bore is round. The bolts are numbered as shown with numbers 1 and 2 on the side with the bearing tabs and the locating dowel. First the bolts are cleaned and the threads, shank and bolt head seat are coated with 6V4876 Molykote Paste Lubricant or Fel-Pro C100 Lubricant. No other lubricant is acceptable and do no allow any of the lubricant to get on any of the connecting rod or bearing mating surfaces.

LERV1450

Pistons, Rings & Liners

Instructor’s Manual Tighten bolts: 1 & 2, 3 & 4, 1 & 2, 3 & 4 Turn 90 Deg. Crush bearing, rod components together 90 deg. stretches bolts

Latest procedure

Page 5

• • • • •

Lesson 5 2001

Tighten bolts 1 and 2 to 90 N•m (66 lb ft). Tighten bolts 3 and 4 to 90 N•m (66 lb ft). Retighten bolts 1 and 2 to 90 N•m (66 lb ft). Retighten bolts 3 and 4 to 90 N•m (66 lb ft). Turn the bolts in sequence an additional 90 degrees

The first four steps “crush” the bearing and bring the connecting rod cap snug against the connecting rod body. The 90 degree turn puts the correct stretch or tightness in the bolts. Note that this is the latest recommended tightening procedure and may be different from prior publications.

Figure 5-8 Assembled Pistons and Rods

Bottom view assembled engine Chamfered sides against crankshaft Flat sides together

This is a bottom view of a 3500 engine with the crankshaft, pistons and connecting rods installed. The chamfer side of the connecting rods are installed so they are against the crankshaft cheeks. The flat sides of the rods are installed against each other.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 6

Lesson 5 2001

Figure 5-9 One Piece Piston

One piece piston forged aluminum skirt cast aluminum crown cast iron band in crown for top rings Oil supplied to gallery by piston cooling jet Pin lubricated through slots

This is a cut view of a one piece piston used on early 3500 engines. It has a forged aluminum alloy skirt and a cast aluminum alloy crown which are electron beam welded together. The crown has a cast iron band that has been cast into it that contains grooves for the top two piston rings. The piston has a cooling gallery to reduce piston temperatures. Oil is supplied to the gallery by the piston cooling jet which sprays oil up into the oil feed port. The piston pin is lubricated through slots that intersect the oil supply port and the port opposite the supply port.

Figure 5-10 One Piece Piston Bottom

Oil gallery drain: port opposite supply port oil drain holes from oil ring groove

Oil escapes from the cooling gallery through another port in the skirt opposite the oil supply port. The oil holes seen on the piston undercrown connect with the oil ring groove to provide an escape for the oil that collects in the oil ring groove

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 7

Lesson 5 2001

Figure 5-11 Pin Lubrication Slot

Single piece piston pin lubricated by gallery oil supply pin lubricated by gallery overflow

With a single piece piston, the piston pin is lubricated by oil coming through a slot in the pin bore. The slot connects to the gallery oil supply tube in one pin bore and with the gallery overflow tube in the other pin bore.

Figure 5-12 2 Piece Piston

2 piece piston first used in Phase I engines copper aluminum bushings in pin bore 2 keystone type combustion rings 1 rectangular oil ring Smaller deeper crater less dead space above crown High strength crown Light weight skirt with good heat dissipation

The 3500 engines first used two piece pistons in some models of the Phase I engines. The pistons have a forged steel crown with copper aluminum bushings in the pin bore. The crown uses 2 keystone type combustion rings and a rectangular type oil ring. This view shows the newer 3500B piston which has a smaller diameter and deeper crater than the older two piece pistons which had a crater resembling the previous single piece piston. This piston is also slightly taller which reduces the crevice volume (dead space) between the top of the piston and the cylinder head. The two piece piston design provides a crown with excellent strength in this high load area and the aluminum skirt saves weight and improves heat dissipation.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 8

Lesson 5 2001

Figure 5-13 2 Piece Piston

Skirt, crown, rod joined by piston pin pin retained by snap rings Piston cooled oil supply port spray to undercrown Pin lubricated by splash oil

The skirt and crown are joined to each other and to the connecting rod by a free floating piston pin. The piston pin is retained on either end by a snap ring in the skirt. The 2 piece pistons are cooled by spraying cooling oil both into the cooling oil supply port and directly up into the undercrown of the piston. The piston pin and the connecting rod small end bearing are lubricated by splash oil coming from the cooling oil.

Figure 5-14 2 Piece Piston

No confined oil gallery Cooling oil from oil supply port and spray oil to crown 2 ports in undercrown to get oil to center

The two piece piston does not have a confined cooling gallery like the one piece piston. The piston crown receives cooling oil not only from the cooling oil port but also from the direct spray into the crown. The skirt retains some oil in a reservoir around the top of the skirt but mostly the oil can move freely around the crown and out as new oil is received. There are 2 oil ports in the crown to help get cooling oil into the center of the undercrown.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 9

Lesson 5 2001

Figure 5-15 Piston Cooling Jets

Cast piston Cooling jet with one piece piston oil into gallery port oil directly into port Two tube PCJ with 2 piece piston Jets retained & aligned

Early 3500 engines with the one piece piston have a cast piston cooling jet (A). Later engines have the fabricated jet (B). They have 2 spray jets, one that sprays oil into the gallery oil supply port and another to spray into the undercrown of the piston for cooling and piston pin lubrication. The jet is retained and held in perfect alignment with the piston gallery supply port by a retainer (C). All engines that have the two piece piston have a 2 tube fabricated cooling jet (B). This jet sprays into the same areas as the one piece piston jets but the volume of oil is much larger. The fabricated jet is retained the same way as the cast jet but with a different retainer.

Figure 5-16 Install Piston Pin Retaining Ring

Piston pin retained by rings in skirt Open end of rings installed toward top

The free floating piston pin is retained on both ends by retaining rings in the skirt of the piston. The latest assembly procedures recommend that the open end of the retaining rings be installed near the top of the ring groove where the piston skirt is strongest.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 10

Lesson 5 2001

Figure 5-17 Piston Ring Installer

Piston ring expander spring & oil ring 180˚ apart second ring up-2 mark up first ring up-1 mark up Index rings 120˚ apart oil ring gap near pin bore

The piston ring expander should be used to install the piston rings. Install the oil ring spring and the oil ring with the end gaps 180 degrees apart. Install the second ring with the up-2 marking toward the top of the piston and install the top ring with the up-1 marking toward the top of the piston. Index the rings so the gaps are 120˚ apart, starting with the oil ring gap near the piston pin bore.

Figure 5-18 Ring Compressor

Preferred piston ring compressor Work well with all piston & ring combinations.

This is the latest and preferred piston ring compressor. A tapered sleeve ring compressor was used early in 3500 engine repair. The compressor shown here works well with all piston and ring combinations with less ring breakage and better control of the piston and rod assembly during installation.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 11

Lesson 5 2001

Figure 5-19 Ring Compressor

Loosen knob Align latch with slot Pull latch bracket away

Loosen the knob on the compressor several turns, align the latch on the side of the bracket with the slot and pull the latching mechanism away from the compressor sleeve.

Figure 5-20 Ring Compressor on Piston

Oil piston & rings Place compressor on piston insert ball in pivot slot swing latch around tighten knob carefully check ring binding

Install piston loosen knob if piston will not slide

Oil the piston and rings well to make installation easier. Use the handles on the compressor to carefully place the compressor over the piston and rings. Insert the ball end of the tightener in the pivot point, carefully swing the latch around to the compressor and turn the latch. Tighten the knob until the compressor is snug on the piston. Continually check that the rings are compressing freely as the knob is tightened. Install the piston and rod assembly. If the piston will not slide through the compressor when installing the piston and rod assembly in the engine, loosen the knob slightly until the piston will start to drop into the engine.

LERV1450 Instructor’s Manual

Pistons, Rings & Liners Page 12

Lesson 5 2001

Figure 5-21 Cylinder Liner & Piston

Replaceable wet cylinder liner induction hardened precision honed crosshatch pattern Filler band 3 o-ring seals Soap for lubricant with oring seals Oil for lubricant with filler band Use immediately after oiled

The 3500 series engines use a replaceable wet cylinder liner. The inner surface is induction hardened for long wear. The bores are precision honed and given a precise crosshatch pattern to give long life and low oil consumption. A filler band is used at the top of the liner to act as a seal after installation. Three o-ring seals near the bottom of the liner seal the coolant into the water jacket and the oil into the crankcase. There is a recommended procedure for installing the cylinder liner. The three o-ring seals, the liner seal grooves and the cylinder block bore are lubricated with a liquid soap as a lubricant for easy installation. The top filler band should be dipped in clean engine oil and installed on the top of the liner just before installing the liner. Oil will cause the filler band to expand and the seal will become uninstallable if the liner is not installed immediately . Note: The piston pin retaining ring is installed incorrectly in this view.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 1

Figure 6-1 Crankshaft & Seals

Crankshaft and Seals

Lesson 6 2001

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 2

Lesson 6 2001

Figure 6-2 3500 Crankshaft

Heavy duty forged crankshaft 3508 - offset rod journals Counterweights removed at overhaul inspected install new bolts lubricate with 6V-4876 Molykote torque per service manual

The 3500 engines have a heavy duty forged and counterweighted crankshaft. The 3508 engines have offset connecting rod journals to provide “even firing” for the 60 degree V-8 engine. The counterweights are bolted onto the crankshaft with 3 bolts. The counterweights must be removed when the engine receives a major overhaul. The weights and crankshaft mating surfaces are inspected and reassembled using all new bolts. The new bolt threads, shank and seats are coated with 6V-4876 Molykote lubricant and installed and tightened according to service manual procedures. Do not allow any of the lubricant to get on the counterweight and crankshaft mating surfaces.

Figure 6-3 Main Bearings

Main bearings groove around upper half supply oil to crankshaft ports supplies oil to rod journals oil supplied by hole in upper half

The main bearings have a groove all around the upper half and part way around the lower half in order to give a continuous supply of pressurized oil to the drilled ports in the crankshaft. These drilled ports supply pressurized lubricating oil to the connecting rod bearings. Oil comes into the bearing through the hole in the top of the upper half of the bearing.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 3

Lesson 6 2001

Figure 6-4 Assembled Main Bearings

Main bearing caps marked Tightening sequence A to D Bolts lubricated with oil Torque plus turn tightening 3/4” bolts - 136 N•m + 210˚ 7/8” bolts - 190 N•m + 180˚

The main bearing caps are marked for location and direction of installation. The word “front” and the part number are installed toward the front. The bolts are lubricated with engine oil and tightened in the A to D sequence shown. The bearing to cap and bearing cap to block mating surfaces should be dry. If the main bearings have the early 3/4 inch bolts, the bolts are first torqued to 136 N•m (100 lb ft) then turned another 210 degrees. If the main bearings have the 7/8 inch bolts, they are first torqued to 190 N•m (140 lb ft) then turned an additional 180 degrees.

Figure 6-5 Crankshaft Gear

Gear on front and rear of crankshaft not the same one bolt off location crank same both ends crank reversed for reverse rotation engines gears marked for timing balancers 2 sets for standard and reverse rotation

A gear is bolted to the front and rear of the crankshaft. The gear trains are different front to rear so the crank gears are not the same. One bolt is off location on each gear so they can be only installed one way. Both ends of the crankshaft are the same so the same gears are used with a reverse rotation engine when the crankshaft is turned end for end. The gears have a mark that is used only with the 3508 engines that have balancers on the front and rear. There are 2 sets of marks, one for standard rotation engines and another set for reverse rotation engines.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 4

Lesson 6 2001

Figure 6-6 Crankshaft Seal Location

Hydrodynamic crankshaft seal “lip” folds over light contact thread like pattern in face crank rotation moves oil Seal adapter until mid 1980’s Seal now in front or rear housing

Most 3500 engines use a hydrodynamic type crankshaft seal. The seal “lip” folds over and runs with very light contact on the wear sleeve The lip has a spiral thread like pattern cut in the face contacting the wear sleeve. Rotation of the crankshaft tends to move any oil back into the engine. Until the mid 1980’s, the crankshaft seal was mounted in an adapter which was installed on the engine. Since then the adapter has been eliminated and the seal is pressed directly into the front or rear housings (lower box)

Figure 6-7 Crankshaft Seal

Hydrodynamic crankshaft seal installed no seal adapter front & rear seals different marked to show crank rotation Installed opposite ends for reverse rotation

This view shows a hydrodynamic crankshaft seal installed in a 3500 engine flywheel housing. This is a newer one without the seal adapter. The front and rear seals are not the same and must be installed in the correct location or oil leakage will be heavy. The seals are marked to show the direction of crankshaft rotation. Reverse rotation engines use the same seals but they are installed on the opposite ends of the engine.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 5

Lesson 6 2001

Figure 6-8 Remove Seal Adapter

Crankshaft seals replaced remove adapters with forcing screws replace seals Newer engines - no adapters drill holes in seal remove with slide impact hammer & 5P-6521 screw tip

Crankshaft seals can be replaced with the front and rear housings in place. Remove the damper or flywheel. On older engines that have seal adapters, remove the 4 retaining bolts. Use 2 of the bolts as forcing screws in threaded holes in the adapter. The seal can then be replaced in the adapter after it has been removed. In the newer engines with the seal installed directly in the housings, drill several holes around the seal and use a slide impact hammer with a 5P-6521 screw tip to remove the seal.

Figure 6-9 Sleeve Remover

5P-7409 distorter to remove sleeve 6V-3143 distorter adapter with seal adapter 1U-7325 distorter adapter with no seal adapter

A 5P-7409 distorter is used to remove the crankshaft wear sleeve. The distorter has a hard sharp edge on it that when forced in contact with the sleeve makes a crease in the surface of the sleeve that expands it. After several creases are made, the sleeve can be easily removed with no damage to the crankshaft. A 6V-3143 distorter adapter is needed with engines having the seal adapter to give proper working space to the distorter. Engines that do not use the seal adapter need a 1U-7325 distorter adapter.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 6

Lesson 6 2001

Figure 6-10 Crimping Sleeve

Distorter adapter and distorter in place turn distorter to crease sleeve moved around sleeve and repeated remove sleeve

The distorter adapter is held in place as shown against the front or rear housing. The distorter is cam shaped and is inserted with the narrow part between the distorter adapter and the wear sleeve. The distorter is turned with a wrench so the sharp edge of the distorter comes in contact with the sleeve then turned some more so the distorter can make a crease in the sleeve and expand it. The distorter and distorter adapter are then move around the sleeve and the process repeated as many times as necessary to expand the sleeve until it can be easily removed by hand.

Figure 6-11 3500 Crankshaft Oil Seal

Crankshaft seal wear sleeve installed sleeve must not be removed rotation arrow dust shield CCW rotation rear-standard rotation eng. front-reverse rotation eng.

New crankshaft oil seals come with the wear sleeve installed. Care must be taken when installing the seal to prevent the sleeve from coming out of the seal. If the sleeve is removed from the seal, the seal cannot be used. This view shows the seal with the crankshaft rotational direction stamped in it, and it shows the wear sleeve and a dust shield. The rotational arrow points counterclockwise so this seal would be installed on the rear of a standard rotation engine or on the front of a reverse rotation engine.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 7

Lesson 6 2001

Figure 6-12 Crank Seal Installation Tools

Seal installation tooling All except D to install seals with adapters D & E used to install seal in adapter A & B and installer similar to C used in engines without adapter

This is the seal installation tooling used to install the crankshaft seals in the older engines having the seal adapter. All items except D are used to install the seal and adapter in the engine. Items D and E are used to install the seal into the adapter. In engines that do not use the seal adapter, items A and B are used and an installer similar to item C is used to install the crankshaft seals.

Figure 6-13 Install Seal in Adapter

Install seal into adapter adapter over forcing brackets seal over adapter forcing ring over seal tighten nuts until seal seated

On engines having the seal adapter the seal is installed in the adapter before it is installed on the engine. Place the adapter over the forcing brackets with the studs on the forcing bracket projecting through the adapter flange. Set the seal over the adapter, place the forcing ring over the seal and install 4 nuts on the studs. Tighten the nuts against the forcing ring to press the seal into the adapter until it bottoms out inside the adapter.

LERV1450 Instructor’s Manual

Crankshaft and Seals Page 8

Lesson 6 2001

Figure 6-14 Install Seal With Adapter

Install seal and sleeve with adapter locator & two guide pins seal and adapter forcing ring and installer nut and tighten until adapter seated Seal & sleeve installed as a unit - do not separate Seal installed dry

To install the seal and adapter, first install the locator on the crankshaft and two guide pins as shown. Install the adapter and seal on the guide pins until the sleeve contacts crankshaft. Install the forcing ring on the pins and the installer on the locator (through the forcing ring). Install the tightening nut and turn until the seal adapter contacts the housing. Both the adapter and sleeve are in place. Note: The seal and sleeve are installed as a unit and at no time should they be allowed to separate. The seal is also installed dry. Any added lubricant could cause problems later.

Figure 6-15 Install Seal Without Adapter

Install seal and sleeve without adapter locator on crankshaft clean crank & seal and coat with retaining cmpd. seal and sleeve on locator installer and nut on locator - tighten

To install the seal not having an adapter, first install the locator to the crankshaft. Clean the crankshaft sleeve location and the inner diameter of the wear sleeve with quick cure primer then coat those surfaces with retaining compound. Place the seal and sleeve assembly over the locator. Install the correct installer and nut and tighten the nut until the installer contacts the locator. Both the seal and sleeve are in place.

LERV1450 Instructor’s Manual

Cooling Systems Page 1

Figure 7-1 Cooling Systems

Cooling Systems

Lesson 7 2001

LERV1450 Instructor’s Manual

Cooling Systems Page 2

Lesson 7 2001

Figure 7-2 Cooling System Function

Cooling systems: dispose of excess heat affect parts fit-up affect lubrication affect thermal efficiency affect wear rate

Cooling systems are a necessary part of any engine. Excess heat is generated during the combustion process and must be removed from the engine or it will be destroyed. Engines are designed to give maximum life and operating efficiency so properly designed cooling systems must also control the operating temperature. The operating temperatures can affect the fit-up of moving parts, lubricating ability of the lubricants, the overall operating efficiency of the engine and the wear rate of the moving components.

Figure 7-3 Engine Heat Sources

Engine heat sources block & heads watercooled exhaust manifolds & variations watercooled turbocharger housings oil cooler jacket water aftercooler

A modern diesel engine may have several heat sources that require cooling. The most common are the block and heads which are closest to the combustion process. Water cooled exhaust manifolds and their variations, turbocharger exhaust housings and turbocharger center housings are also common options with some applications. Most all diesel engines have an oil cooler to remove excess heat from the lube oil and jacket water aftercoolers also contribute to the heat input into the cooling system.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 3

Figure 7-4 Overheating Problems

Overheated engine - hotter oil: reduced lubricating ability & oil film thickness reduced running clearance scuffing & seizing of moving parts

An engine that runs too hot will also have hotter oil. Hotter oil will be thinner, thus reducing the lubricating ability. The oil film between moving parts will be thinner so there will be less running clearance between the moving parts which may increase friction between moving parts. Inadequate lubrication will cause failure from scuffing of the moving parts in contact with each other and in extreme conditions will cause the moving surfaces to seize.

Figure 7-5 Overcooling Problems

Overcooled engine - problems oil contamination & engine sludging increase deposit formation with ring sticking and high wear reduced efficiency and higher fuel consumption

An engine that runs too cool will have problems also. Water that condenses in the crankcase will cause rapid oil contamination and sludging inside the engine. Colder piston and ring temperatures can cause increased deposit formation on the pistons and in the piston ring areas. The heavy deposits can cause piston ring sticking and high ring and liner wear. The wear rates of other components can also be affected. Higher oil viscosities and colder engine operating conditions will reduce the engine efficiency and increase fuel consumption.

LERV1450 Instructor’s Manual

Cooling Systems Page 4

Lesson 7 2001

Figure 7-6 Engine Water Flow

Components: water pump oil cooler cylinder block & heads water manifold aftercooler regulators bypass line Coolant flow water pump oil cooler & aftercooler cylinder block & heads water manifold regulators

Upper inset: cold coolant condition regulators closed Lower inset: regulators open coolant to radiator or heat exchanger Actual operation: regulators partially open controls to desired operating temperature

Cooling system components are shown as follows: water pump (1), oil cooler (2), cylinder block and heads (3), water manifold (4), aftercooler (5), water temperature regulators (6), and the bypass line from the regulators to the water pump (7). With jacket water aftercooled engines, coolant enters the water pump from the regulator housing return line or the external cooling circuit. The coolant flow divides at the pump outlet with part of the coolant going through the oil cooler and part going to the aftercooler. After the coolant passes through the oil cooler and the aftercooler, it enters the engine block at the rear of the engine. Once in the engine block, it is directed to flow evenly to the cylinders, first cooling the cylinder liners and block and flowing upward into the cylinder heads to cool the heads. Coolant flows from the heads to the water manifolds and then to the water temperature regulators. The regulators direct the coolant flow to give the engine the correct coolant temperature. The upper cutaway inset of the regulator schematic shows a cold coolant condition with the regulators closed and sending the coolant straight through the regulators and back to the water pump inlet. The lower inset shows the regulators fully open with all coolant flowing to a cooling heat exchanger or radiator. In actual operation the regulators would be only partially open, sending coolant through both outlets in the correct proportion to control the operating temperature of the engine to the desired level.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 5

Figure 7-7 Jacket Water Aftercooler Circuit

Coolant flow of a JWAC engine Water cooled turbocharger housings an option

This schematic shows the coolant flow of a jacket water aftercooled engine. Coolant flows from the water pump through the aftercooler and oil cooler, the engine and the regulators. The regulators send some coolant through a radiator or heat exchanger for cooling and the rest through a bypass line to the water pump. This view also shows some coolant flowing to the turbocharger. Water cooled turbocharger housings are an option with some applications.

Figure 7-8 Separate Circuit Aftercooler Water Flow

Separate circuit aftercooling: own circuit water pump, regulators, heat exchanger Advantage: higher ratings higher efficiency Disadvantage: 2 complete cooling systems

Separate circuit aftercooling gives the aftercooler it’s own cooling circuit. As with the engine circuit, the aftercooler circuit has a water pump, water temperature control regulators or thermostats, and a cooling radiator or heat exchanger. Separate circuit aftercooling has the advantage of producing cooler combustion air which has higher oxygen density. This allows higher ratings and improves engine efficiency. The disadvantage of the separate circuit system is that it requires two complete cooling systems. Some marine applications use sea water aftercooling which pumps sea water directly through the aftercooler with no water temperature control. Most 3500B and 3500 high displacement engines use separate circuit aftercooling.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 6

Figure 7-9 Inlet Controlled Cooling System

Inlet control cooling system: heat exchangers expansion tank at inlet temperature consistent coolant temperature to engine seldom used with radiator cooling

Inlet control cooling systems are most commonly used with heat exchanger cooled systems. Coolant flowing into the expansion tank is a mix of bypass and cooled water and is at the desired inlet temperature. This minimizes temperature cycling and gives a more consistent coolant temperature to the engine. The inlet controlled system is seldom used with radiator cooling.

Figure 7-10 Outlet Controlled Cooling System

Outlet control system: consistent outlet temperatures set maximum engine temperature energy recovery good up to 127 ˚C outlet cold and cyclic expansion tank temperatures

The outlet control cooling system is typically used with radiators. It provides a consistent outlet temperature and can set a maximum engine temperature. This makes the control system a requirement for energy recovery systems. The outlet temperature can be set as high as 127 ˚C (260 ˚F) for efficient energy recovery. The expansion tank coolant temperature can be very cold in cold operating locations and can be very cyclic as load changes occur.

LERV1450 Instructor’s Manual

Cooling Systems Page 7

Lesson 7 2001

Figure 7-11 Jacket Water Pump

Jacket water pump centrifugal gear driven

This is a cutaway of a 3500 engine jacket water pump. It is a centrifugal pump that is driven by the front gear train.

Figure 7-12 Auxiliary Pump for Separate Circuit Aftercooler

Aftercooler circuit pump gear driven centrifugal closed circuit Coolant temperature regulator

This gear driven centrifugal pump is used for the separate circuit aftercooler circuit and is usually used with a closed fresh water system. A coolant temperature regulator may be part of the circuit to control the temperature of the water to the aftercooler to a desirable temperature. Too high a temperature reduces the benefits of an aftercooler and too low a temperature may cause undesirable water condensation in the combustion air circuit.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 8

Figure 7-13 Sea Water Aftercooler Pump

Sea water aftercooler pump gear driven salt water applications water taken from ocean, pumped through aftercooler and returned to ocean filter screen before pump

This is a gear driven sea water aftercooler circuit pump that is generally used in salt water marine applications. It is designed to be corrosion resistant to handle salt water and small debris. Cooling water is taken directly from the ocean, pumped through the aftercooler then returned back to the ocean. A filtering screen is installed before the pump.

Figure 7-14 Water Cooled Exhaust Manifold

Cooled exhaust manifolds water cooled air shielded air passage insulator water passage cooling reduced cooling requirements more energy in exhaust Improve efficiency Insulated blankets & metal shields used now

Marine engines and some other applications require cooled exhaust manifolds and turbocharger housings. This view shows a cutaway of the water cooled and air shielded manifolds used on engines prior to the B series engines. The manifolds consist of an inner liner for the exhaust gases, an air passage around the exhaust manifold and a cooling water passage around the air passage. The air passage acts as an insulator to reduce the amount of heat transfer to the coolant. This reduces the need for increased cooling system capacity and leaves more energy in the exhaust gases thereby improving engine efficiency. Insulated blankets and sheet metal shields are used when needed on engines now.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 9

Figure 7-15 Water Temperature Regulators

Water temperature regulators inlet control regulators closed flow straight through

Engine operating temperature sleeve moves down start flow block-off at seat open flow at top of sleeve mix cool water

Sensing bulbs

Heat Exchangers tube type plate type keel cooler radiator

Replace regulators at 6000 hours or if failed

This cutaway view shows water temperature regulators in a 3500 engine that is set up as an inlet control system. The regulators are closed as shown. Coolant from the water manifolds passes freely upward between the seats and sleeves, through the regulators to the upper housing and into the expansion tank. As the coolant temperature reaches the engine operating temperature, the sleeves in the regulators will move downward. This will start to block off flow entering between the seats and the bottom of the regulators but will open up a port in each regulator in the heat exchanger return line port, thus mixing coolant from the water manifolds and cooled water from the heat exchanger in sufficient quantities to maintain the desired coolant inlet temperature. The sensing bulbs control the position of the sleeves and the thus the flow through the heat exchanger. Heat exchangers referred to in this discussion can be tube type or plate type heat exchangers, keel coolers or radiators. The water temperature regulators play a very important role in providing long engine life and efficient engine operation. The regulators should be replaced every 6000 hours when the coolant is replaced or as needed if the regulators cannot maintain the desired engine coolant temperature.

LERV1450 Instructor’s Manual

Cooling Systems

Lesson 7 2001

Page 10

Figure 7-16 Coolants & Maintenance

Increased operating temperatures improve efficiency reduce wear Correct coolant important

Diesel engine manufacturers have increased engine operating temperatures to improve engine efficiency and increase engine life. Cooling system maintenance is an important part of overall engine maintenance. Using and maintaining the correct coolant is an important part of any maintenance program.

Figure 7-17 Coolant Boiling Point

Boiling point important pressure altitude antifreeze

Pressurized cooling systems 50 to 104 kPa common

With the higher operating temperatures seen today, the coolant boiling point becomes more important. The boiling point of a coolant varies dependent on the pressure at which the coolant operates, the altitude at which the engine operates and the amount and type of antifreeze in the coolant mixture. Most cooling systems operate under pressure with 50 kPa (7 psi) to 104 kPa (15 psi) being most common.

LERV1450 Instructor’s Manual

Cooling Systems Page 11

Lesson 7 2001

Figure 7-18 Engine Coolants

Coolants: water ethylene glycol & water mix 60% concentration maximum poor heat transfer properties above 60%

The most common coolants used with diesel engines are water and an ethylene glycol and water mix. Ethylene glycol which is most commonly referred to as antifreeze is used for freeze protection and for raising the boiling point of the coolant. However, a coolant should never have more than a 60% concentration of ethylene glycol as ethylene glycol has very poor heat transferring properties by itself and the ability of the coolant to do it’s job falls off rapidly with concentrations above 60%.

Figure 7-19 Antifreeze & Boiling Point

Ethylene glycol & water mix most common coolant higher % = lower freeze Higher % = higher boil 60% plus pressure = 260 ˚C max boil point

Ethylene glycol mixed with water is the most common antifreeze coolant. The higher the concentration of ethylene glycol the lower the freezing point. Likewise the higher the concentration of ethylene glycol, the higher the boiling point of the coolant. Pressurizing the cooling system to the maximum allowable with a 60% concentration can raise the boiling point to as high as 127 ˚C (260 ˚F).

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Cooling Systems

Lesson 7 2001

Page 12

Figure 7-20 Water Quality

Coolant mixtures: water & SCA water, antifreeze & SCA

Coolant mixtures generally consist of water and a supplemental coolant additive (SCA) or water mixed with antifreeze and a SCA.

Water for coolant most efficient low cost universally available not all drinkable water satisfactory may form acids & scales

Water is used because it is the most efficient, low cost, universally available heat transfer agent. However, each water source contains various levels of contaminants. At one time, any water that was drinkable was considered acceptable. With the high engine operating temperatures of the modern diesel engines even some drinkable water supplies may have minerals, chemicals and other contaminants that will form acids or scales that will reduce cooling system service life.

Acceptable water: distilled or deionized water with limits - Fig 7-20 test all water supplies

Never use salt water

Sea water aftercooling corrosion resistant components continual supply cool water

For the best service life from the cooling system, Caterpillar recommends using distilled or deionized water. Distilled water is readily available and not too expensive in most locations. In the event distilled or deionized water is not available, Figure 7-20 gives the maximum limits of the most common contaminants. Any water supply that is to be used for diesel engine coolant should be tested. Never use salt water or sea water as an engine coolant under any circumstance. Even limited time running with sea water can form harmful deposits and corrosion. Engines equipped for sea water aftercooling are constructed with corrosion resistant components in the aftercooler circuit and can use sea water in that circuit. The sea water is continually taken in and dumped after passing through the aftercooler circuit. The temperature of the coolant never gets very high.

LERV1450 Instructor’s Manual

Cooling Systems Page 13

Lesson 7 2001

Figure 7-21 Coolant Conditioning

Supplemental coolant additives prevent rust, scale, mineral deposits all metals protected

Correct concentration manufacturers recommendation Too low - poor protection Too high - deposits & water pump wear

Caterpillar antifreeze - adequate protection SCA depletion Extended life - 3000 hr. extender heavy duty - test and add as required

Good quality water only SCA not good for gasoline engines

Water or water mixed with antifreeze should never be used alone as a coolant. Supplemental coolant additives (SCA) or cooling system conditioners must also be used. SCA’s help prevent rust, scale and mineral deposits from forming. All metals including aluminum are protected. If antifreeze is not used, 6 to 8% SCA should be used in the coolant. With a 50/50 mix of water and antifreeze, a 3 to 6% level should be maintained. Regardless of the brand of conditioner, the correct concentration must be used. Follow the manufacturers recommendation. if the concentration is too low, the engine will have inadequate protection. If the concentration is too high, the additive itself can cause deposit formation and accelerated water pump seal wear. Coolants using the recommended amounts of Caterpillar antifreeze will have sufficient SCA to start out. Many commercial antifreezes may not and will require additional SCA to be added. The SCA materials in the coolant will become depleted as they do their job so additional SCA will have to be added periodically. Extended life coolants do not have to be tested periodically but must have an extender added at 3000 hours or at half the life of the antifreeze, which ever comes first. Regular Caterpillar and commercial heavy duty antifreezes should be tested every 250 hours and additional additive added to the coolant as necessary to bring the concentration level up to recommendations. Note: No amount of supplemental coolant additives will make a poor quality water acceptable. The water must meet minimum requirements. Also, supplemental coolant additives and antifreeze with high levels of SCA are for diesel engines and should not be used in gasoline engines.

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Figure 7-22 Antifreeze

Preferred coolants: Cat ELC preferred Commercial ELC acceptable 50/50 mixture no testing

One time addition of extender at half life

Caterpillar Extended Life Coolant is the recommended coolant for all 3500 engines. Commercial extended life coolants that meet the Caterpillar EC-1 specification are also acceptable. These antifreezes when mixed 50/50 with water will provide freeze protection down to -36 ˚C (-33 ˚F) and corrosion protection for half the life of the antifreeze without any need for periodic testing or addition of supplemental coolant additives. A one time addition of an ELC extender is made to the coolant at 3 years or 3000 hours, whichever occurs first.

Cat ELC diesel, HD spark ignited gas, automotive

Acceptable coolants: Cat DEAC & SCA 3 year service life Commercial HD antifreeze & SCA 1 or 2 year life 50/50 mixture

Propylene glycol acceptable 50/50 mixture maintain same as HD antifreezes Uses fishing boats environmentally sensitive areas less harmful

Caterpillar supplies extended life coolants for diesel, heavy duty spark ignited gas engines and automotive applications. An acceptable but less desirable coolant is a 50/50 mix of Caterpillar heavy duty Diesel Engine Antifreeze/Coolant (DEAC) or commercial heavy duty coolant/antifreeze and SCA. The service life of the Caterpillar DEAC is 3 years and requires testing every 250 hours with addition of SCA as needed. Commercial heavy duty antifreezes should be changed after 1 or 2 years use depending on the quality of the antifreeze. A 50/50 mixture of propylene glycol and water is an acceptable coolant and is maintained the same as a heavy duty ethylene glycol. Propylene glycol is required in some applications such as fishing boats that process the fish on board the vessel and utilize engine heat from the coolant through heat exchangers. Engines operating in environmentally sensitive areas may also require the use of propylene glycol as a coolant. Propylene glycol is not considered as harmful to humans and the environment as ethylene glycol.

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Figure 8-1 Fuel Systems

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Figure 8-2 Fuel System Schematic

Unit injector fuel system 1. inlet line 2. fuel transfer pump 3. fuel filters 4. hand priming pump 5. fuel injectors 6. fuel manifolds 7. fuel pressure control valve 8. fuel return line

Spin-on filter shown Commercial filters same

Excess fuel for injector cooling Return fuel to main tank Return to day tank will require fuel cooler

High fuel temperature: reduced power injector deposits failure

The 3500 diesel engine fuel systems are designed with each cylinder having its own unit injector. Fuel enters the fuel transfer pump (2) through the inlet line (1) from the fuel tank and primary fuel filter and water separator. From the fuel transfer pump the fuel moves through separate fuel lines to the fuel filters (3) and the hand priming pump (4). The hand priming pump also pumps fuel into the fuel filters. From the fuel filters the fuel is piped to the fuel supply manifolds (6) on each side of the engine. At each cylinder a small fuel supply line delivers fuel to a port in the cylinder head which supplies fuel to a cavity around the fuel injector (5). On the opposite side of the head, a port in the head moves surplus fuel to a fuel return line which supplies fuel to a fuel return manifold. Fuel in the return manifolds is piped to a fuel pressure control valve (7) which is mounted on the front of the right side fuel manifold. From the fuel pressure control valve, fuel returns back to the main fuel tank (8). This view shows a fuel system with spin-on fuel filters. The commercial front mounted fuel filters are designed into the fuel system in the same way. The fuel system pumps four times as much fuel as the engine can consume at full load. This surplus fuel cools the injectors. The fuel usually is piped back to the main fuel tank so the fuel can cool naturally from the bulk of the fuel in the tank. If a day tank must be used in the installation, then a fuel cooler must be installed in the fuel return line. Fuel temperature to the engine should not be above 66 ˚C (150 ˚F). Higher fuel temperatures will reduce the maximum power output from the engine and increase the risk of injector deposits and failure.

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Figure 8-3 Vehicle Fuel System

Fuel transfer pump positive displacement gear type pressure relief - 860 kPa check valve Spin-on filters typically vehicle engines available most applications Hand priming pump - long or short

This view shows the fuel transfer pump, spin-on fuel filters and the hand priming pump. The fuel transfer pump is a positive displacement gear type pump. It has a pressure relief valve that returns fuel back to the inlet of the pump if the discharge pressure exceeds 860 kPa (125 psi). There is also a check valve in the pump near the outlet that prevents fuel from flowing through the pump when the hand priming pump is used.The spin-on type filters are typically used with vehicle engine installations but they are an option for nearly all applications. A long hand priming pump is shown, but a shorter pump will also be found on 3500 engines with the spin-on filters.

Figure 8-4 Fuel Filter Service

Replace filters close fuel supply & return remove filter lube filter gasket with diesel fuel hand tighten to gasket contact Tighten additional 3/4 turn

Spin-on filters are easily replaced. With the engine shut down and the fuel supply and return lines closed, remove the filter elements with a filter wrench. Lubricate the seals of new filters with diesel fuel and hand tighten until the gasket touches the filter base. Tighten an additional 3/4 turn. Do not overtighten. Fuel filters are generally changed when the oil and oil filters are changed. For marine and

LERV1450 Instructor’s Manual Fuel filters changed with oil & oil filters More filters for long hour applications Differential pressure for long hour changes 104 kPa max. differential

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industrial applications, more filters are used to extend the service life. In any case the filters should be changed if the differential pressure exceeds 104 kPa (15 psi). In long hour applications, a differential pressure gauge or 3500B electronics continuously measures the pressure difference from the inlet to the outlet. Fuel pressure is not a good indicator of plugged filters.

Figure 8-5 Commercial Fuel Filter and Pump

Marine, generator set, industrial - filter across front of engine 5 replaceable elements Replace elements shut off fuel drain filter remove elements install new elements fill filter with fuel

Hand priming pump fill filter housing after filter change after repair Fuel boost pump No priming necessary

Duplex fuel filter option 2 elements service filter with engine running Service 1000 hr. or 104 kPa differential

Commercial engines such as those used in marine, generator set and other industrial applications usually have a fuel filter that is mounted across the front of the engine above the oil filters. The filter has 5 replaceable elements inside it. To replace the elements when the engine is shut down, shut off the fuel supply and return lines, open a drain valve (not visible in this view) and drain as much fuel as possible from the filter housing. Remove the cover on the end of the housing and remove the elements. Install new elements, replace the cover and fill the filter housing with fuel. The hand priming pump shown here is an option that is used to fill the filter housing after a filter change. It is also used to fill the fuel system and prime the injectors after repair work is completed on the engine. The hand priming pump is a necessity unless the installation has a fuel boost pump to supply fuel to the engine which can also be used to prime the fuel system. In normal operation, the fuel system does not need to be primed before starting unless the fuel system has been serviced or the engine has set for a long period of time without running. A duplex fuel filter attachment is an option that allows the main fuel filters to be changed with the engine running. The duplex filter has two elements that filter the fuel while the main filters are changed. The fuel filters are normally changed at 1000 service hours, but the filters should be changed earlier if the differential pressure exceeds 104 kPa (15 psi). Differential pressure monitoring is required.

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Figure 8-6 Fuel Manifold & Pressure Control Valve

Fuel delivery manifolds fuel supply lines drilled ports Fuel return drilled ports fuel return lines return manifolds Fuel pressure contrail valve 415 - 450 kPa

Fuel is delivered to the fuel injectors by the fuel manifolds, fuel lines from the manifolds to the cylinder heads and through drilled ports in the cylinder heads. Excess fuel which is supplied to the injectors to cool the injectors returns to the fuel tank through drilled ports on the other side of the head, fuel return lines and through fuel return manifolds. Return fuel from both sides of the engine must pass through a fuel pressure control valve which is located at the front of the right side fuel manifold. This valve controls the fuel pressure to the injectors at 415 - 450 kPa (60 - 65 psi).

Figure 8-7 Mechanical Unit Injector

MUI fuel systems EUI or MEUI fuel systems MUI this section

The 3500 diesel engines utilize two types of fuel systems, the mechanical unit injection system (MUI) and the mechanically actuated electronic unit injection system (referred to as EUI or MEUI). The next part will discuss the MUI system.

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Figure 8-8 Caterpillar Unit Injector

Caterpillar mechanical unit injector Pump and nozzle in one unit no high pressure lines efficient fuel injection tappet & spring rack bar 4 fill ports with screens calibration screw - factory set

This is a Caterpillar mechanical unit injector. The unit injector has the pump and spray nozzle in one component. This concept eliminates high pressure fuel lines and gives much better fuel injection characteristics for greater engine efficiency. A mechanism driven by the camshaft pushes on the tappet which pumps the fuel. The tappet return spring returns the tappet at the end of the pumping stroke. The rack bar controls the amount of fuel pumped on each stroke. Fuel enters the injector through four ports which have debris screens built in. The calibration screw is factory set and should not be disturbed.

Figure 8-9 Unit Injector Components

UI Components close fitting plunger & barrel scroll position controls fuel pumped

This is a cutaway view of an older type unit injector but the Caterpillar designed injector has the same basic internal components. The plunger has a very close fit with the barrel to prevent seepage from the high pressure fuel during the injection stroke. As the plunger moves down in the barrel during the pumping stroke, the position of the scroll relative to the upper and lower ports in the barrel control the amount of fuel pumped.

LERV1450 Instructor’s Manual Rack rotates plunger Check valve spring, check valve, nozzle tip 3100 - 4100 kPa

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The rack rotates the plunger to control the position of the scroll. The check valve spring holds the check valve into the nozzle tip to prevent leakage of fuel into the cylinder when the injector is not pumping. When the internal pressure exceeds 3100 - 4100 kPa (450 - 595 psi) the check valve will lift off the seat and allow fuel to spray out of the nozzle orifices.

Figure 8-10 Unit Injector and Control Mechanisms

Unit injector & control mechanisms rotate camshaft lifter & pushrod rocker arm injector tappet and spring lifter roller in contact with cam lobe

Fuel rack governor torsional shaft control lever control rod bell crank lever

Control rod adjusting screw for synchronizing spring in top solid for fuel-increase spring for fuel-off shut down with seized injector

This shows the unit injector with it’s individual cylinder control mechanisms. Fuel injection is made by the rotation of the camshaft (1). The camshaft lobe pushes up on the lifter and pushrod (2) which then pushes up on one end of the rocker arm (3). The other end of the rocker arm pushes down on the injector tappet and spring (8) which in turn causes the pumping action within the injector that sprays fuel into the cylinder. As the cam lobe moves away from the lifter the spring on the tappet returns the mechanism back to the start. When the injector is timed, the rocker arm will be adjusted so that the lifter roller never leaves the camshaft lobe surface. The amount of fuel that is pumped with each stroke is determined by the position of the fuel rack (12). The fuel rack is moved by linkage which starts with a hydraulic or electrically controlled governor that is connected by torsional shafts to the control lever (9), control rod (10) and bellcrank lever (11) at each cylinder. The control rod (10) serves 2 special purposes. An adjusting screw in the top end provides the adjusting point for the injector rack. The racks for all the cylinders must be synchronized so all the injectors pump the same amount of fuel at any rack setting. The control rod also has a spring in the upper end that is solid in the increase-fuel direction but can deflect in the fuel-off direction. This is a safety link that allows the engine to safely shut down if there is an injector seizure that freezes up the fuel rack in that injector.

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Figure 8-11 Fuel Control Linkage

Fuel control linkage injector, rack, bellcrank, control rod, control lever torsional control shafts, cross shaft, ball & slot swivel connections

Rack limit lever governor output shaft right or left mount

Two linkage adjustments click stop screw synchronize injectors rack limit screw limits fuel to cylinders

Rack limit screw factory adjusted

This is a drawing of the complete fuel control linkage. As we saw in the previous view, the rack (6) position in the fuel injector (7) is controlled by movement of the control linkage: bellcrank lever (5), control rod (4) and control lever (3). This linkage which is at each cylinder connects to a hollow torsional shaft on each side of the engine (1 & 8). The left side and right side shafts are connected by a hollow cross shaft (9). Ball and slot swivels connect the three shafts to give equal movement to all of the individual cylinder control rods. A rack limit lever (12) connects to the torsional shaft and is moved by a lever that is attached to the governor output shaft (10). The governor and rack limit lever can be mounted on either the right front of the engine as shown or on the left front if the engine is equipped with a front gear housing having accessory drive locations on the left side. There are two linkage adjustment points that are important. There is a click stop adjustment screw in the top of the control rods (11) that is adjusted to synchronize the injectors so all pump the same amount of fuel. Item 2 is the rack limit or power setting screw. It limits the maximum travel of the fuel control linkage and the fuel racks, and therefore the maximum fuel the injectors can deliver to the cylinders. The rack limit screw makes contact with the fuel limit lever. The rack limit screw is adjusted at the factory, should not need field adjustment, and if it does, should only be adjusted by a qualified service technician.

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Figure 8-12 3161 Governor

3161 governor - MUI vehicular, marine, industrial pneumatic speed control electric shutoff mechanical and pressure shutoff boost sensitive smoke limiter

The Woodward 3161 hydraulic governor is one of the governor options found on mechanically unit injected engines. These governors are typically used in vehicular, marine and some industrial applications. A pneumatic speed control (A) is available as an option. Item B is an electric shutoff which is available as either energize to run or energize to shut down. A mechanical and a pressure actuated shutoff are also available. Item C is a boost sensitive smoke limiter that is now standard on the 3161 governors.

Figure 8-13 EG10PC Electric Governor Actuator

Electric governors generator sets EG10PC actuator 2301A control 700 series controls

Electric governors are another option on 3500 engines and are most typically found on generator set engines. An EG10PC governor actuator controls the engine fuel system linkage. A Woodward 2301A electric governor control is one of the more common controls used. The 700 series programmable controls are also used.

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Figure 8-14 Rack Stop Lever & Cross Shaft Connection

Rack limit lever to right control shaft Slot and ball connection to cross shaft Similar ball and slot connection to rotate left control shaft

The rack limit lever is attached to the right side control shaft in this view. A lever on the governor output shaft engages the slot in the rack limit lever. The control shaft on the left side is operated by connections to the cross shaft. The slot in the rack limit lever engages the ball end of a lever on the cross shaft to rotate it. A similar ball and slot connection at the left side of the cross shaft rotates the left side control shaft when the cross shaft is rotated.

Figure 8-15 Control Rod Lever

Control rod lever connects to control shaft

At each cylinder on both sides of the engine, a control rod lever is connected to the control shaft. The other end of the control rod lever is connected to the control rod which connects to the bell crank lever and the rack bar on the injector.

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Figure 8-16 Cross Shaft

Cross shaft

This is the cross shaft that connects the right and left fuel control shafts.

Figure 8-17 Bell Crank Lever & Injector Rack

Bell crank lever injector rack

The control rod is attached to the bell crank lever which in turn engages the injector rack.

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Figure 8-18 Rack Limit Screw

Full fuel position rack limit lever rack limit screw solid limit Torque rise in 3161 governor

This view shows the rack limit lever in the full fuel position. It is stopped from giving the engine more fuel by the rack limit screw. This is a solid stop so no added torque rise can be built in at this location. Vehicular applications requiring extra torque rise or special torque characteristics will still have this mechanical limit as a maximum fuel position but will have the torque rise characteristics built into the 3161 governor and all the control will take place at fuel settings below the mechanical rack limit setting.

Figure 8-19 Remove Injector

Remove injector cover rocker arms & pushrods fuel lines control rod retaining nut bell crank & support pry out injector.

To remove the injector, remove the rocker arm cover, the rocker arms and pushrods, the fuel supply and return lines (shown in place here) and the injector hold down clamp. Plug and cover the fuel lines and fittings. Remove the control rod end retaining nut, disconnect the control rod and remove the bell crank lever and support. Carefully pry on the injector to lift it out of the head.

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Figure 8-20 Unit Injector Out

Injector out clean injector bore no fuel in cylinder

This view shows the top of the cylinder head with the injector out. The injector bore should be cleaned before an injector is installed again and the cylinder should be checked to be sure no fuel has run into the cylinder when the injector was removed. Normally the fuel lines are removed before the injector is removed to minimize fuel leakage into the cylinder.

Figure 8-21 Install Injector

Install injector clean new seals oil seals & bore set in place install clamp tighten clamp & torque reassemble linkage & components synchronize & time injectors

Before installing the injector, clean the seating surfaces and replace the o-ring seals. Liberally oil the seals and the injector bore and carefully set the injector in the bore. Install the clamp and bolt, and tighten the bolt to press the injector into the head. Torque the bolt and check that the rack moves freely. Do not drive on the injector tappet to push it into the head. Install the fuel linkage and top end components. Reset injector synchronization and timing.

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Figure 8-22 Synchronize Injectors

Set reference position remove synchronizing pin from cover remove left plug

To synchronize the racks or check the rack limit position, the linkage first has to be set to a reference position. Remove the synchronizing pin from it’s storage position in the rack limit cover. Remove one of the plugs that gives access to the rack limit lever. The left one as you face the cover is usually the one to be removed.

Figure 8-23 Synchronizing Pin

Remove washer from sync pin

The washer must be removed from the sync pin before it is installed to prevent an incorrect reference position. The rack limit screw cover is removed in this view to show the rack limit screw. Normally the cover will not be removed. The lower cover bolt is wired and sealed to prevent the removal of the cover except by a qualified serviceman.

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Figure 8-24 Install Sync Pin

Install synchronizing pin & tighten

Install the synchronizing pin all the way into the hole and tighten it lightly with a wrench to give the most accurate reference position.

Figure 8-25 Move Racks to Maximum

Advance fuel linkage to maximum. weight on 3161 governor governor over-ride weight EG10PC held or tied in position do not start in maximum fuel position

Advance the fuel linkage to the maximum fuel-on position. When it is in this position the rack limit lever will be against the synchronizing pin similar to the view in Figure 8-18. This view shows a service weight installed to the 3161 governor output shaft to hold it in the maximum fuel position. The weight is adequate to hold the linkage in position but light enough for the governor to over-ride it if it is accidentally left on the governor. With an EG10PC actuator, the linkage will have to be held manually or tied in the maximum fuel-on position. Do not start the engine with the linkage tied in this position or the engine may be destroyed from overspeed.

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Figure 8-26 Synchronizing Gauge

Synchronizing or thickness gauge in fuel timing kit

A special synchronizing or thickness gauge is supplied in the fuel timing kit to use when synchronizing the injectors.

Figure 8-27 Gauge on Rack Bar

Gauge over rack bar reference position thickness gauge rocker arms & pushrods off or on engine

The 12.7 mm (.50 in.) gauge is inserted over the rack bar when the fuel linkage is in the reference position previously set. The gauge is then used as a thickness gauge to adjust the rack bar position. The injectors can be synchronized with the rocker arms and pushrods removed as shown here, but this operation is normally done with them in place.

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Figure 8-28 Adjusting Control Rod

Adjust linkage click stop screw take screwdriver off “feel” adjustment gauge between rack bar head & calibrating screw Calibrating screw set at factory - do not change “Flip” linkage & recheck

Adjust the linkage by turning a click stop screw in the top of the control rod one click at a time. Take the screwdriver off the control rod and check the “feel” of the gauge. Readjust until the gauge just fits between the rack bar head and the calibrating screw head on the injector. The calibrating screw has no internal function on the injector but provides a seating surface for the gauge. This screw position is set at the factory and must not be changed. When the adjustment “feels” correct, reach down to the bell crank lever, lift slightly then let go. Recheck the adjustment with the gauge.

Figure 8-29 Install Dial Indicator

Rack limit not reset but checked remove plug install collet install long extension and indicator push into collet until zeroed tighten collet

The rack limit normally does not need to be reset but it can be checked. Set the injector linkage to the reference position. Remove the plug from the hole on the right side of the cover and install a collet. Install a long extension from the fuel timing kit on to the dial indicator from the kit. Place the indicator in the collet and push it in until all the pointers on the indicator are at zero. Tighten the collet.

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Figure 8-30 Adjust Rack Limit

Maximum fuel position Unscrew sync pin rack limit against screw read power setting on indicator Cover bolt wired and sealed adjust only by qualified serviceman.

With the fuel linkage held in the maximum fuel-on position, unscrew the synchronizing pin until the rack limit lever contacts the rack limit screw. The reading on the indicator is the present fuel setting and should be close to the full load fuel setting on the engine information data plate. If it is not, then the rack limit screw which is shown here with the cover removed can be adjusted by a qualified serviceman. The lower bolt on the rack limit cover is wired and sealed and only a qualified serviceman can make the adjustment and reseal the cover.

Figure 8-31 Crankshaft Timing

Set engine top center no. 1 cylinder Timing bolt & timing location plug Timing locations both sides

The engine must be set at top center number one cylinder before the valve, bridge and injector timing adjustments can be made. To do this, remove the timing bolt and the crankshaft timing location plug from the front of the flywheel housing. There are timing locations on both sides of the housing and either side can be used.

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Figure 8-32 Crankshaft Timed

Time engine remove cover install rotating tool rotate crankshaft to align hole screw in bolt then remove determine compression or exhaust stroke adjust 1/2 bridges & valves time 1/2 injectors

Remove the other bolt and the small cover. Install a turning tool in the hole and rotate the crankshaft in the engines’ normal rotation until a threaded hole in the flywheel aligns with the hole in the flywheel housing. When the timing bolt can be screwed into the flywheel, the engine is timed to top center number one cylinder and half the bridges and valves can be adjusted and half the injectors can be timed. It will now have to be determined if the timing is on compression or exhaust stroke.

Figure 8-33 Determine stroke

Determine stroke find valve open check service manual identify stroke

With the valve covers removed, check a cylinder with a valve that is open. Go to the service manual Systems Operation Testing and Adjusting book and determine the stroke. For instance, if the number 3 cylinder intake valve on a standard rotation 3512 engine is open, we can see that the engine is on top center number one cylinder exhaust stroke because the number 3 intake valve cannot be adjusted and it is adjustable when set on the compression stroke.

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Figure 8-34 Adjust Bridges

Valve bridge adjustment prior to valve lash adjustment loosen lock nut & screw push down on bridge turn screw cw until touch tighten 20 - 30˚ light touch

The valve bridges should always be adjusted prior to adjusting the valve clearance (lash). Loosen the locknut and turn the adjusting screw counterclockwise one turn or until the adjusting screw no longer touches the end of the valve. Push downward on the rocker arm at the point where the rocker arm makes contact with the bridge with a force of at least 1 pound. Turn the adjustment screw clockwise until the screw contacts the end of the valve then turn an additional 20 to 30 degrees. A very light touch is required to be able to feel contact when tightening the screw.

Figure 8-35 Tighten Locknut

Torque locknut 30 N•m Dial indicator method

Torque the locknut to 30 N•m (22 lb. ft.). Be sure the screw does not turn when the nut is torqued. The bridges can also be set using a dial indicator but because of the confined working space, the previous method is usually preferred.

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Figure 8-36 Valve Lash Adjusting Tools

Valve lash adjustments thickness gauge early dial indicator gp. except EUI later dial indicator gp. except aluminum fuel manifolds

Valve clearance (lash) adjustments can be made using a thickness (“feeler”) gauge, however an easier and more accurate way is to use a dial indicator. A dial indicator can also be used to quickly and easily check the valve lash without loosening the lock nut and adjusting screw. This view shows the tools used to measure and set the valve lash. The tool on the left can be used for all 3500 engines with mechanical unit injectors. The tool on the right is the newest design and can be used on all 3500 engines except early engines with the aluminum fuel manifolds.

Figure 8-37 Check Valve Lash.

Early tool 125-2742 base 125-2743 collar metric or inch dial indicator 2 feet & spring rocker pushed away from bridge Set engine TC #1 cylinder

The early tool shown again here is made up of a 125-2742 base, a 125-2743 collar with a collet and either a metric or inch dial indicator. The base has 2 feet, one that slides inside the other and contacts the dial indicator. The two feet slide in between the rocker arm and bridge when installed on the engine. A spring pushes the two feet apart, thereby pushing the rocker arm away from the bridge. Set the engine at top center number one cylinder and determine which valves can be checked and adjusted.

LERV1450 Instructor’s Manual Tap rocker arm adjusting screw to seat roller Install tool lift screw end of rocker arm set zero release rocker arm read lash check clearance adjust clearance if required torque lock nut check lash

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To ensure the lifter roller is seated firmly on the base circle of the camshaft, tap each rocker arm on top of the adjusting screw with a soft hammer before the tool is installed. Install the tool and lift or pry up on the adjusting screw end of the rocker arm so the valve lash is zero. Turn the dial indicator face to zero. Release the rocker arm to go to maximum valve clearance and read the valve lash on the dial. If the lash needs to be changed, loosen the lock nut and turn the adjusting screw clockwise to reduce the valve lash or counterclockwise to increase the valve lash. Torque the lock nut to 70 N•m (50 lb. ft.) and check the valve lash. Readjust if necessary.

Figure 8-38 Check Valve Lash B Series

B series engines 147-5482 gauge group set engine TC #1 cylinder tap rocker arm install gauge group

move valve end of rocker arm to remove oil film 147-2059 torque wrench 147-2060 socket adapter

raise torque wrench zero lash zero indicator lower torque wrench maximum lash adjust if necessary check and adjust if necessary

The 147-5482 valve lash gauge group is used to adjust the valve clearance on the B series engines and later engines with the tube type fuel manifolds. Set the engine at top center number one cylinder and determine which valves can be checked and adjusted. Tap each rocker arm on top of the adjusting screw with a soft hammer before the gauge group is installed. Install the gauge group. Move the valve end of the rocker arm up and down several times to remove most of the oil film for more accurate readings. This can be done with the hands or with a wrench. The 147-2059 torque wrench and 147-2060 socket adapter are part of the valve lash kit. Place the adapter on the torque wrench and place on the rocker arm lock nut. The rocker arm can be adjusted with this setup. Raise the torque wrench to give zero clearance of the rocker arm and bridge. Set the indicator to zero. Lower the torque wrench and the weight of the torque wrench will move the rocker arm to maximum valve lash. If the valve lash is within acceptable range, move to the next valve. If it is not, loosen the lock nut and turn the adjusting screw clockwise to reduce the valve lash or counterclockwise to increase the valve lash. Hold the screw and torque the lock nut. Check the valve lash and readjust if necessary.

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Figure 8-39 Timing Kit

Timing kit MUI EUI gauge block, base, indicators, wrenches, synchronizing gauge, collets, extension rods, case

This view shows the 9U-5132 timing kit that is used to make adjustments to mechanical and electronic unit injectors in 3500 engines. The kit consists of a reference gauge block (A), magnetic base (B), dial indicator (C), optional digital indicator (D), 2 collet wrenches (E), rack synchronizing gauge (F), several collets and extension rods, and a case.

Injector Timing precise & simple must follow procedures half injectors set TDC #1 compression half set TDC #1 exhaust

Injector Timing

Dial indicator, magnetic base, 87. 00 mm reference Timing set best performance, low fuel consumption, low smoke & emissions Most engines set other than reference Correction preset in dial indicator 1. Set TDC #1 - determine stroke & injectors to be set

Timing the injectors is a precise but simple process, however you must follow the service manual procedures exactly or the timing will be incorrect. Half the injectors can be timed with the engine crankshaft pinned at TDC #1 cylinder compression stroke and the other half can be adjusted when the crankshaft is rotated 360 degrees to TDC #1 cylinder exhaust stroke. The procedure follows. The procedure utilizes the dial indicator, magnetic base and the 87.00 mm ledge on the reference gauge block. Engine timing is set on an engine to give the best performance, lowest fuel consumption, and lowest smoke and emissions. Most engines therefore, will have a timing dimension other than 87.00 mm. A correction will be preset on the dial indicator in reference to the 87.00 mm gauge block to give the individual engine the correct timing. 1. Set the engine at TDC #1 cylinder and determine which stroke the engine is on and which injectors can be timed.

2. Fuel Timing dimension on engine data plate

2. Find the Fuel Timing dimension on the engine data plate.

3. Calculate Dial Indicator Setting or determine from service manual

3. Calculate the Dial Indicator Setting or determine the setting from the 3500 Engine Service Manual for the Fuel Timing dimension found on the engine data plate.

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Figure 8-40 Timing Calculation

Calculate dial indicator setting data plate - gauge block 87.40 - 87.00 = +.40

The dial indicator setting (preset) is a simple calculation. The dial indicator setting is the engine data plate dimension minus the reference gauge block dimension. For example, if the engine data plate timing is 87.40 mm: 87.40 - 87.00 = +.40 mm. That is the value that will be preset into the dial indicator when checking and adjusting the timing.

Figure 8-41 Timing Calculation

86.40 - 87.00 = -.60 Notice minus sign - important Easier to calculate than determine from limited service manual numbers.

Example 2: If the engine data plate dimension is 86.40 mm, the dial indicator setting is 86.40 - 87.00 = -.60mm. Notice the minus sign on the -.60 mm calculation. This is important to make the correct dial indicator setting. it is important to be able to calculate the dial indicator setting rather than rely on the service manual as the service manual chart only lists a few of the potential settings and it is easier to calculate the setting rather than determine the desired number from the values in the chart.

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Figure 8-42 Injector Timing

Timing dimension tappet to base held by rocker arm injector plunger in when timed plunger in more to start injection camshafts timed same all engines

Timing dimension larger, timing retarded more cam rotation to inject

Timing dimension less timing advanced less cam rotation to inject

The timing dimension is the distance from the top of the unit injector spring retainer (tappet) to the top of injector body base. This drawing shows an injector set to some timing dimension which is held by the injector rocker arm when the injector lifter is on the camshaft base circle. The injector tappet and plunger is pushed in (downward) from it’s uninstalled position. Also note that the tappet must be pushed in more before the injector starts to pump fuel. It is this additional plunger travel that controls the timing since the camshafts are timed the same on all 3500 engines. If the timing dimension is larger than the reference gauge block dimension (87.00 mm), the timing will be retarded from the reference. The injector plunger has to be pushed in further to reach the start of injection; the crankshaft and camshaft have to rotate more in the engine cycle. If the timing dimension is less than the reference gauge block dimension (87.00 mm), the timing will be advanced from the reference. The injector plunger has to be pushed in less to reach the start of injection; the crankshaft and camshaft have to rotate less in the engine cycle.

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Figure 8-43 Zero Indicator

Resume timing process

4. Assemble rod, collet, dial indicator, magnetic base Set on gauge block 87.00 mm ledge Set face with zero at top Move indicator to zero all pointers on dials temporary setting do not move dial face

Starrett - 3 dials & pointers Federal - 2 dials & pointers Both 6V-3075 & acceptable only 6V-3075 acceptable

We will now resume the timing process and set up the dial indicator for timing. 4. Assemble the long extension rod, collet and dial indicator onto the magnetic base. Set the base on the gauge block so the end of the extension rod rests on the lower (87.00 mm) ledge. Set the zero on the dial face at the top of the indicator. With the collet lock nut set only finger tight, carefully move the dial indicator up or down until the pointers on all the dials are on zero. This is only a temporary starting point. Do not move the dial face to get the zero point. This view shows the Starrett indicator with three dials and pointers. A Federal indicator may be in some kits as the same 6V-3075 part number. The Federal gauge has only two dials and pointers. Both gauges are acceptable and only the 6V-3075 gauges are acceptable for timing the unit injectors on 3500 engines.

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Figure 8-44 Dial Indicator Preset

5. Move indicator to set pointer to preset example: +.40 mm tighten collet

5. Gently move the dial indicator so that the large pointer moves to the dial indicator setting determined in step 2. For our example, push the indicator down to rotate the pointer clockwise until it indicates +.40 mm. Tighten the collet.

Positive setting - pointer clockwise Negative setting - pointer counterclockwise black no.'s positive red no.'s negative Do not rotate dial face

Note: The pointer must rotate in a clockwise direction to get a positive dial indicator setting. The pointer must rotate in a counterclockwise direction to get a negative dial indicator setting. The black numbers on the 6V-3075 indicator are positive and the red numbers are negative. Do not rotate the dial face to set the number on the pointer.

Figure 8-45 Install Timing Tool

6. Place tool on injector spring retainer extension rod contacting base & free to move

6. Place the magnetic base and indicator on the top of the unit injector spring retainer. The extension rod must be in contact with the top surface of the unit injector base, free to move up and down, and not touching the injector spring or the clamp.

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Figure 8-46 Adjust the Timing

7. Adjust rocker arm screw pointers all on zero torque locknut recheck dial indicator recheck indicator on gauge block

7. Turn the injector adjusting screw until all the pointers on the dial indicator are on their zero marks. Tighten and torque the lock nut. Check that the pointers are still on zero. Reset if necessary. Place the timing indicator back on the reference gauge block to check that the setting is still correct.

Figure 8-47 Digital Indicator

Digital Indicator different procedure program to 87.00 mm increase - rod extend decrease - rod pushed in set tool on injector adjust to data plate timing Incorrect programming common problem Use extreme care

An alternate method of timing the injectors uses the digital indicator instead of the analog dial indicator. The procedure is different with the digital indicator. First program the indicator as described in the service manual to read 87.00 mm when it is on the reference gauge block. Check to be sure the readings increase as the extension rod is extended and decrease as the rod is pushed inward. Set the tool on the injector retainer as with the dial indicator and adjust the injector rocker arm until the indicator reading is the same as the injector timing dimension on the engine data plate. Incorrectly programming the plus or minus (+ or -) direction each time the digital indicator is used is a common problem so extreme care must be used.

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Figure 8-48 3500 EUI

3500 EUI 1992 machine application 1995 B Series 1997 Phase I option 1999 3500 HD MEUI reference

In 1992, 3500 engines with Electronic Unit Injection (EUI) were introduced for Caterpillar machine applications. In 1995, series B 3500 engines were first produced and offered to the market utilizing only an EUI fuel system. In 1997 EUI was offered as an option on the phase I engines and in 1999 3500HD engines were introduced with an EUI fuel system. EUI fuel systems are also referred to as Mechanically Actuated Electronically Controlled Unit Injection (MEUI) systems. This lesson will use the shorter EUI designation and cover the 3500B EUI fuel system.

Figure 8-49 EUI System Features

EUI MEUI 152 mPa fuel pressure fuel vaporization injector mechanism strengthened

The 3500B electronic unit Injection fuel system has many advantages over the mechanical unit injection system. One of the main components of the EUI fuel system is the mechanically actuated electronically controlled fuel injector. It is a precision made component that can deliver 152 mPa (22,000 psi) fuel pressure to the injector spray nozzle orifices at full engine rating for better fuel vaporization. The injector mechanism, from a wider camshaft lobe and wider lifter roller to the heavier rocker arm, is strengthened for longer life.

LERV1450 Instructor’s Manual EUI similar to MUI except: electric solenoid control no rack & scroll less mechanism same fuel transfer pump, filters, manifolds & piping

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The basic fuel injector is similar to the mechanical fuel injector but it uses an electric fuel solenoid valve to control fuel injection instead of the rack and scroll of the mechanical injector. This reduces considerably the amount of mechanical components and also the maintenance and adjustment time required on the fuel system. Other than the electronic fuel injectors, the EUI engines use most of the same fuel system components as the MUI system, such as the fuel transfer pump, filters, manifolds and piping.

Figure 8-50 Electronic Features

Components ECM programmed computer personality module precise fuel delivery best operating characteristics

Electric speed governing torque rise, smoke limiting, rack stop Variable injection timing lower fuel consumption reduced smoke, emissions

Cold start assistance Altitude compensation

Engine monitoring and protection

Besides the EUI injector, the major electronic components of the EUI fuel system are the Electronic Control Module (ECM) and the electronic sensors. The sensors feed inputs into the ECM and the ECM sends an electric signal to the injectors to give very precise fuel delivery. The ECM is primarily a computer that can be programmed to give the best operating characteristics for any application and operating condition. It is teamed with a personality module that is unique to each application. Electronic speed governing eliminates the need for a governor and linkage and the ECM can be programmed for torque rise, smoke limiting and rack limiting. The ECM provides the fuel system with variable injection timing to give an ideal timing for nearly any operating condition, with reduced fuel consumption, smoke and emissions. The ECM can improve cold start functions with fuel limiting and timing changes to reduce white smoke and harmful startup cylinder pressures. Timing and fuel control is programmed to provide ideal operation at higher altitudes. Accurate diagnostic information is available on a continuing basis. All system failures are automatically reported to the operator. Alarms and shutdown features can be programmed into the system for engine protection

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Figure 8-51 EUI & MUI Mechanical Components

EUI & MUI Components EUI injector, rocker arm, shaft, lifter, pushrod, return spring MUI mechanical rack linkage

This cutaway view shows a comparison between the EUI and MUI mechanical components. The view on the left shows the electronic unit injector, the stronger rocker arm, rocker arm shaft, lifter and pushrod. The pushrod also has a return spring. The right view shows the mechanical unit injection components with the mechanical rack linkage that the EUI system does not have.

Figure 8-52 EUI & MUI Component Comparison

MUI & EUI actuating mechanisms component differences EUI pushrod return spring lifter in contact with cam lobe constantly reduce wear and failure aggressive cam lift profile shorter injection duration

This view shows a comparison of the MUI (top) and EUI fuel injectors and their actuating mechanisms. The differences between the mechanical and electronic unit injectors, the rocker arms, pushrods, and lifters can be seen. The EUI pushrod has a return spring which reacts against a boss cast into the rocker base. The return spring keeps the lifter against the camshaft lobe at all times to reduce wear and camshaft and lifter failure. This feature is necessary with the very aggressive cam lift profile which has a shorter injection duration.

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Figure 8-53 EUI Mechanical Components

Mechanical Components same as MUI except injector fuel supply water separator & primary filter fuel transfer pump electric or hand priming pump engine driven gear type fuel transfer pump pressure relief valve 860 kPa check valve fuel through ECM

electric priming pump hand priming pump fuel filters fuel supply manifolds

fuel supply lines fuel return lines fuel return manifolds fuel pressure control valve 415 - 450 kPa fuel pressure Spin-on and commercial fuel filters available

With the exception of the unit injectors, the mechanical components and fuel circuit are the same as the mechanical unit injected engines. Fuel is taken from a fuel supply tank and pulled through a water separator and primary fuel filter. From the primary fuel filter and water separator, fuel flows to the fuel transfer pump and an electric or hand priming pump. The fuel transfer pump is an engine driven gear type pump. It has a pressure relief valve that returns some fuel to the pump inlet if the system fuel pressure exceeds 860 kPa (125 psi). There is also a check valve at the pump outlet to prevent fuel flow through the pump when the priming pump is used. Fuel from the fuel transfer pump flows through the ECM to cool it. Fuel from the ECM and priming pump flows to the fuel filters and then to the fuel supply manifolds on each side of the engine. At each cylinder a small fuel supply line delivers fuel to a port in the cylinder head which supplies fuel to a cavity around the fuel injector. On the opposite side of the head, a port in the head moves surplus fuel to a fuel return line which supplies fuel to a fuel return manifold. Fuel in the return manifolds is piped to a fuel pressure control valve which is mounted on the front of the right side fuel manifold. The fuel pressure control valve maintains the fuel supply pressure at 415 to 450 kPa (60 - 65 psi). From the fuel pressure control valve, fuel returns back to the main fuel tank. Both spin-on and front mounted commercial filters are available on the EUI engines.

LERV1450 Instructor’s Manual Surplus fuel to cool injectors Fuel piped to main fuel tank Fuel cooler with day tank Maximum fuel temperature 66 ˚C higher - reduce power output, injector deposits, failure potential

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The fuel system pumps four times as much fuel as the engine can consume at full load. This surplus fuel cools the injectors. The fuel usually is piped back to the main fuel tank so the fuel can cool naturally from the bulk of the fuel in the tank. If a day tank must be used in the installation, then a fuel cooler must be installed in the fuel return line. Fuel temperature to the engine should not be above 66 ˚C (150 ˚F). Higher fuel temperatures will reduce the maximum power output from the engine and increase the risk of injector deposits and failure.

Figure 8-54 Electronic Unit Injector

Electronic unit injector mechanically actuated electronically controlled injection start & stop points variable precise metering & injection timing

The electronic unit injector is mechanically actuated and electronically controlled. It combines an electronic actuator, pump and nozzle in a single compact unit. Both start and stop points of injection are infinitely variable for precise fuel metering and injection timing for any application and operating condition.

Fuel supply cylinder head confined by seals debris screens

Fuel is supplied to the injector from a cavity in the cylinder head and is confined between the o-ring seals (A) on the injector. The fuel passes through debris screens (B) in the injector body to enter the injector.

Continuous fuel flow ECM signal 105 volts Close fuel exit plunger pressurizes fuel sprays from nozzles

Fuel flows continuously in and out of the injector. When the ECM energizes the injectors' solenoid (C) with a 105 volt signal, the injectors' exit is closed. As the plunger is pushed down into the barrel via the camshaft and mechanism, the fuel trapped in the injector is pressurized and sprays through the nozzle orifices (D) into the combustion chamber.

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Figure 8-55 Fuel Priming Pumps

Electric or hand priming pump maintenance and repair not run for long time vehicular application hand pump most common electric pump in vehicular applications prime & easier start

An electric or hand priming pump is used to prime the fuel system after maintenance or repair or when the engine has not run for a long time. This view shows both a hand priming pump and an electric priming pump in a vehicular application. The hand priming pump is the most common pump used. The electric pump is an option that is often used in vehicular applications to make priming the fuel systems easier. The pump is controlled from the cab and can also be used at startup to make the engine easier to start.

Figure 8-56 High Efficiency Fuel Filters

Control valve wear dirt in fuel from 5 - 10 mu filters from environment or fuel 1996 2 micron filters available 1999 standard double component wear life

When the first electronic unit injectors started operation high wear in the control valve was seen with some diesel fuels in some applications. Very fine abrasives from the work environment or in the delivered fuel were passing through the standard fuel filters with a 5 to 10 micron rating. In 1996 Caterpillar introduced the 2 micron filter for EUI engines. In 1999 the filters became standard on all 3500 diesel engines. The 2 micron filters are for all applications. These filters have been found to more than double injector component life.

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Figure 8-57 Electronic System

EUI fuel system ECM sensors electronic fuel injectors customer interface monitoring devices ECM personality module programming output to injectors Inputs throttle, camshaft position, atmosphere, turbocharger, fuel, oil, crankcase, coolant, aftercooler, exhaust

Monitoring devices operating conditions engine performance protection alarms derate shutdown

The electronic part of the EUI fuel system consists of the engine control module, engine sensors, electronic fuel injectors, customer interface (inputs & outputs) and engine monitoring devices. An example of an EUI system is shown. It has an Electronic Control Module (ECM) with a personality module or programming for a particular application, engine, rating and operating condition. The ECM sends the electrical signals to the fuel injectors at the appropriate times to pump precisely measured fuel into the cylinders. The output of the ECM is calculated by the ECM based on many inputs. These inputs are throttle position, camshaft position, atmospheric pressure, turbocharger outlet pressure, filtered and unfiltered fuel pressure, turbocharger inlet pressure, filtered and unfiltered oil pressure, crankcase pressure, coolant flow, aftercooler temperature, engine coolant temperature, exhaust temperature and others. Monitoring devices can be connected to the ECM to monitor operating conditions and engine performance. Some of the monitoring devices can be set up to protect the engine with alarms, derating, and shutdown.

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Figure 8-58 Electronic Control Module

ECM totally contained computer power supply controls engine Personality module ADEM II Operator & sensor inputs optimize engine efficiencies control engine - injectors diagnostic information

ECM 23 to 27 volts DC 2 40 pin connectors fuel cooled

Cat data link EMCP II EMS II communicate with ECAP & ET

Personality module software fuel setting information Reprogram new module flash programming

The ECM is a totally contained computer with a built-in power supply for circuit boards, sensors and actuators, central processing unit, and memory devices. It controls the engine. The ECM has a personality module that is the software for the computer. Together they form the ADEM II Electronic Engine Control and Monitoring System. The system processes information from operator and sensor inputs to precisely optimize engine efficiencies and then control the engine through the electronic unit injectors. Accurate diagnostic information is available on a continuous basis with all system failures reported to the operator. The ECM requires a 23 to 27 volt DC power supply. Two 40 pin connectors are used for engine and OEM wiring harnesses. Fuel from the fuel transfer pump passes through the case of the ECM to cool the internal components. The fuel then passes on to the fuel filters. A Cat Data Link is included to display engine status parameters on the Electronic Modular Control Panel II (EMCP II) or Electronic Monitoring System II (EMS II). The data link is also used to communicate with an Electronic Control Analyzer Programmer (ECAP) or Electronic Technician (ET). The personality module contains the software with all the fuel setting information such as horsepower, torque rise, and air/fuel ratios which determines how the engine will perform. There are two ways to change these parameters: remove and replace the personality module or electronically reprogram the personality module (Flash Programming).

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Figure 8-59 Speed/Timing Sensor

Speed/timing sensor left rear gear housing signal to ECM crankshaft position rotation direction RPM Timing wheel 3 pairs slots different

This a speed/timing sensor that is mounted in a machined hole on the left side of the rear gear housing. It sends a signal to the ECM, providing information for determining crankshaft position, direction of rotation and the number of RPM. A timing wheel is mounted against the left rear camshaft gear and is pinned to the camshaft to give the wheel a reference position to the engine crankshaft. Three slots are cut differently in the wheel to generate a signal necessary for timing. Refer to the Service Manual for sensor adjustment procedures.

Figure 8-60 Jacket Water Temperature Sensor

Jacket water temperature sensor cold mode timing over temperature shutdown aftercooler & oil temperatures Exhaust temperatures alarm or derate

This is a jacket water temperature sensor. It is a sealed heat-soak sensor that passes jacket water temperature on to the ECM to determine cold mode injection timing and over-temperature shutdown. Similar sensors measure aftercooler water and oil temperature of the engine and attachments. These sensors look similar but use different type signals so they are not interchangeable. A high temperature sensor measures exhaust temperature and through the ECM can provide a high temperature alarm or engine derate.

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Figure 8-61 Pressure Sensor

Pressure sensors 0 - 5 VDC pressure readout map comparison trigger alarm, derate, shutdown

The ECM receives data from several pressure sensors such as the one shown above. The sensors provide a 0 to 5 VDC analog signal which is converted to a pressure value. These values are available for direct pressure readout and can also be compared with pressure maps programmed into the ECM. If the pressure is outside programmed limits for any operating condition, the ECM can trigger an alarm, derate the engine or shut the engine down. The ECM also uses the pressure inputs to control engine performance for various operating conditions.

Figure 8-62 Throttle control

Engine speed control programmed outside source marine load share PDM converter position transducer vehicular applications

Engine speed can be programmed into the ECM or the ECM can receive a speed demand signal from an outside source. This view shows a typical marine engine control , a generator set load share module, a PDM converter (speed brick) that combined with a potentiometer manually controls engine speed, and a position transducer used in vehicular applications with hand and foot throttle controls.

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Figure 8-63 EMCP II+

Vehicle dash panel start & stop operation readouts

Figure 8-57 refers to a dash panel and display which would be typical for a vehicular type application. It would include start and stop controls and engine operating condition readouts.

EMCP II+ connected to ADEM II, injectors, sensors control for generator sets program operational parameters check diagnostics monitor operation

This view shows the Electronic Modular Control Panel II (EMCP II+). It is connected with the ADEM II, the injectors and the sensors to provide an electronic modular control for generator set applications. The EMCP II+ lets the user program operational parameters, check diagnostics at a glance and visually monitor operating conditions.

LCD readouts oil pressure coolant temperature RPM & hours volts, amps, frequency

LCD readouts (A) are provided for direct readout of engine oil pressure, coolant temperature, RPM and engine running hours. System DC volts, generator AC volts, AC amps and frequency can also be read from the display.

Additional start-stop control emergency stop voltage control adjustable crank & cooldown LED’s - protection & diagnostics

There is an automatic start-stop control (B), an emergency stop push button (C), a generator voltage control potentiometer (D), and an adjustable cycle cranking and cooldown timer. Flashing LED indicators for protection and diagnostics (E) include low oil pressure, high coolant temperature, low coolant level, overspeed, overcrank and emergency stop. Spare indicators and more control options are available.

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Figure 8-64 Electronic Monitoring System II

EMS II - marine & other applications main display & alert gauge clusters engine control switch emergency stop switch instrument module control switches alarm & alarm silence switch pyrometers

Main display engine hours engine speed diagnostic codes gauge values unit and service indicators 10 alert indicators - trigger alarm, derate, shutdown

The EMS II (Electronic Monitoring System) is standard for marine engines but can be used with other applications. The panel is the control and information center for the system and houses: A. main display and alert indicator module B. gauge clusters (1 to 3) C. engine control switch D. emergency stop switch E. instrument module control switches F. alarm and alarm silence switch G. pyrometers. The main display (A) has a six digit readout for engine hours, engine speed, diagnostic codes, actual numerical information from the gauge clusters and ten unit and service indicators. The display also has ten alert indicators which are used to identify abnormal engine conditions that have triggered a warning, derate or shutdown.

Gauge clusters relative values temperatures pressures

The gauge clusters (B) have “gauges” that give relative values to various engine temperatures and pressures in the engine. Actual numbers have to be taken from the readout one at a time.

Engine control switch OFF/RESET AUTO

The engine control switch (C) has four positions. The OFF/RESET position removes power from the engine. The AUTO position powers up the ECM and allows it to monitor a remote start and stop switch similar to this switch.

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Engine control switch MANUAL START STOP

The MANUAL START position starts the engine crank sequence and allows the engine to continue running once started. The Stop position places the engine in cooldown mode and shuts it down.

Emergency stop button quick stop air shutoff activated not for normal shutdown remote emergency stop button

The emergency stop button (D) brings the engine to a quick stop for protection during emergency situations. Power is removed from the ECM and the air shutoff is activated if the engine has one. This button should not be used for normal engine shutdown. Remote emergency stop buttons can also be connected into the panel.

Instrument module control switches interface with main display module

The instrument module control switches (E) interface with the main display module to bring up different readings on display.

Alarm activated by main display module Silence button turn off alarm correct less than 5 minutes

The alarm (F) is activated by the main display module whenever there is a system alarm, a parameter out of range or an active diagnostic. The alarm silence button (F) lets you turn off a sounded alarm. The alarm is silenced, but if the engine continues to run and the problem is not corrected in five minutes or a new condition is detected, the alarm will sound again.

Pyrometer panel option no panel interface 16 exhaust temperatures 2 turbo out temperatures readout only - no protection or control

The pyrometer (G) is an option that can be installed in the panel but has no interface with the electronics in the panel. The pyrometer has positions for 16 exhaust temperatures and two turbocharger exhaust outlet temperatures. The pyrometer is a readout only and has no protection or control capabilities.

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Figure 8-65 EUI Mechanical Adjustments

Valve, & bridge adjustments required same as MUI engines Injectors mechanically “timed”

EUI fuel systems have eliminated many of the mechanical adjustments required by the mechanical fuel systems. However, valve and bridge adjustments are still required and the injector must be mechanically “timed” by setting the rocker arm. Valve and bridge adjustments are the same as with the mechanically injected engines and will not be covered here. Refer to page 18 for that procedure. EUI mechanical “timing” follows.

Figure 8-66 Set Zero

Set engine top center #1 determine cylinders

Assemble timing fixture set rod on 64.34 step Zero indicator

1. Set the engine to top center number one cylinder and determine from the service manual which injectors can be set. Install a 1220451 extension rod and collet in the appropriate hole in the magnetic timing fixture. 2. Place the timing fixture on the reference gauge block so the extension rod rests on the higher 64.34 mm step (arrow). Install a short indicator tip on the dial indicator, place the indicator in the collet and tighten the collet with the fingers. Move the indicator up or down until all the pointers are on zero. Tighten the collet.

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Figure 8-67 Adjust Rocker Arm

Base & indicator on injector

Adjust rocker arm all pointers on zero torque lock nut recheck check gauge block

3. Place the magnetic base and indicator on the top of the unit injector spring retainer. The extension rod must be in contact with the timing shoulder of the unit injector, free to move up and down, and not touching the injector spring or the clamp. 4. Turn the injector rocker arm adjusting screw until all the pointers on the dial indicator are on their zero marks. Tighten and torque the lock nut. Check that the pointers are still on zero. Reset if necessary. Place the timing indicator back on the reference gauge block to check that the setting is still correct.

Figure 8-68 Time ECM

Engine timing sensor 24 tooth gear special tooth pattern tolerance stack-up inaccurate timing

Engine timing is determined by sensor input from the special 24 tooth gear mounted on the rear of the left camshaft. A special tooth pattern allows the ECM to determine stroke and piston position of the number one cylinder. However, a tolerance stack-up of the sensor and gear locations can cause the timing to be inaccurate enough to affect engine performance.

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Flywheel TDC hole accurate used to calibrate pickup offset stored

The TDC hole in the flywheel is very accurate and can be used to calibrate the speed/timing pickup. During the calibration process the the inaccuracy is determined and an offset value (correction) is determined and stored in the ECM.

Timing Calibration Sensor sensor calibration magnetic pickup timing pin hole temporary or permanent engine running

The Timing Calibration Sensor (arrow in Figure 8-68) is installed in the flywheel housing, when required, for speed/timing sensor calibration. On some engines this magnetic pickup sensor is temporarily installed in the hole normally reserved for the timing pin when setting top center number one cylinder. Some engines have the calibration sensor permanently installed. Calibration is done with the engine running.

Calibration required new ECM replace sensor

The calibration procedure must be repeated any time the ECM or the speed sensor is replaced.