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32

CHAPTER OVERVIEW

This chapter introduces the student to the internal combustion engine. A variety ofpopular designs are described and a general discussion of engine diagnosis and testingis introduced.

CHAPTER OBJECTIVES

Describe the various ways in which engines can be classified.Explain what takes place during each stroke in the four-stroke cycle.Outline the advantages and disadvantages of the in-line and V-type engine designs.Define important engine measurements and performance characteristics, includingbore and stroke, displacement, compression ratio, engine efficiency, torque, andhorsepower.Explain how to evaluate the condition of an engine.List and describe nine abnormal engine noises.Outline the basics of diesel, stratified, and Miller-cycle engine operation.

INSTRUCTIONAL OUTLINE WITH TEACHING HINTS

I. Introduction to EnginesII. Engine Construction

III. Engine Classifications

A. Design Features1. Operational Cycles2. Number of Cylinders3. Cylinder Arrangement4. Valve Train Type5. Ignition type6. Cooling System7. Fuel Type

Hint: Give examples of various engine classifications.

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B. Four-Stroke Gasoline Engine1. Intake Stroke2. Compression Stroke3. Power Stroke4. Exhaust Stroke

C. Two-Stroke Gasoline Engine

D. Characteristics of Four-Stroke Engine Design1. In-Line Engine2. V-Type and W-Type Engines3. Slant Cylinder Engine4. Opposed Cylinder Engine

E. Valve and Camshaft Placement Configurations1. Overhead Valve (OHV)2. Overhead Cam (OHC)

F. Valve and Camshaft OperationG. Engine Location

1. Front Engine Longitudinal2. Front Engine Transverse3. Mid-Engine Transverse

Hint: Describe changes in engine designs and discuss how engines willchange in the future.

H. Gasoline Engine Systems1. Air/Fuel System2. Ignition System3. Lubrication System4. Cooling System5. Exhaust System6. Emission Control System

III. Engine Measurement and Performance

A. Bore and Stroke1. Oversquare2. Undersquare

B. DisplacementC. Compression Ratio

1. Variable Compression Ratio EnginesD. Engine Efficiency

1. Volumetric Efficiency2. Thermal Efficiency3. Mechanical Efficiency

E. Torque versus HorsepowerHint: Discuss how displacement, compression, torque, and horsepower affect

engine performance.IV. Engine Identification

A. VINB. Underhood Label

Hint: Have the students use the VIN and the underhood label to identify themodel years and engine sizes of an assortment of vehicles.

V. Engine DiagnosticsA. Compression TestB. Cylinder Leakage Test

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C. Cylinder Power Balance TestD. Vacuum TestsE. Oil Pressure Testing

Hint: Discuss when each of these tests would be the most useful. Describethe difference between a compression test, a cylinder leakage test, and acylinder power balance test.

VI. Evaluating the Engines ConditionVII. Noise Diagnosis

A. Using a StethoscopeB. Common Noises

1. Ring Noise2. Piston Slap3. Piston Pin Knock4. Ridge Noise5. Rod-Bearing Noise6. Main or Thrust Bearing Noise7. Tappet Noise8. Abnormal Combustion Noises

Hint: Describe the various noises and whether they happen at crankshaftor camshaft speed. If possible, record some normal and abnormal enginenoises for playback to the students.

VIII. Other Engine DesignsA. Diesel EngineB. Rotary EngineC. Stratified Charge EngineD. Miller-Cycle EnginesE. Hybrid Vehicles

Hint: Assign students to find magazine articles about new engine designs.

ANSWERS TO TEXTBOOK REVIEW QUESTIONS

1. The combustion chamber is the space between the top of the piston and the cylinderhead. It is an enclosed area in which the gasoline and air mixture is burned.

2. The four strokes are intake, compression, power, and exhaust.3. As an engines compression ratio increases, there should also be an increase in the

octane rating of the fuel in order to avoid abnormal combustion. Gasoline with toolow an octane rating may ignite before spark occurs due to the additional heat pro-duced by a higher compression ratio, or it may burn in an explosive and destructivemanner.

4. A cylinder balance test can be used to compare the efficiency of each cylinder. Ideally,all of the cylinders should produce an equal amount of power.

5. Tappet noise is a term used to describe a noisy valve train. It is characterized as a lightregular clicking noise, which is more noticeable at idle speed. Because the camshaftrotates at one-half crankshaft speed, valve train noises may be identified by a lowerfrequency.

6. b. Gasoline engines are only one of a variety of internal combustion engines.7. a. The ignition of the fuel/air mixture begins the power stroke.

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8. c. The compression ratio describes the amount that the air/fuel mixture will becompressed.

9. a. The camshaft opens and closes the intake and exhaust valves.10. a. A diesel engine may have a compression ratio of up to 25:1.11. d. Because a compression test is performed while cranking the engine and a cylinder

leakage test is performed while the crankshaft is stationary, the results may vary

between these tests.12. c. Piston slap is a hollow, bell-like noise that is produced when the piston slaps against

the cylinder wall due to excessive clearances. It is commonly heard when the engineis cold, and gets louder when the engine is accelerated. Shorting out the spark plugof the affected cylinder may quiet the noise.

13. a. The exhaust system.14. In four stroke cycle engines, the order of the strokes is: intake, compression, power,

and exhaust. In the engine, mentioned in the question, when cylinder #1 is on thepower stroke, cylinder #2 will be on its compression stroke, cylinder #4 will be on theintake stroke, and cylinder #2 will on the exhaust. Therefore, when cylinder #1 is onits compression stroke, cylinder #3 will be on its intake stroke.

15. b. The stroke of an engine is twice the crankshaft throw.16. True. Worn or damaged piston rings can cause air to be found escaping around the

dipstick tube during a cylinder leakage test.17. c. Both technicians are correct. When an engine is cold, the oil pressure will be high-

er due to the viscosity of cold oil. An oil pressure regulator valve that is sticking canalso cause abnormally high oil pressure.

18. a. A sharp metallic rapping sound originating from the upper portion of an enginewould most likely be a piston pin knock. A damaged or worn crankshaft thrust bear-ing would result in a dull steady knock originating near the bottom of the engine.

19. b. A collapsed lifter would most likely not show up on either a compression or acylinder leakage test, but would cause the cylinder to produce less power thanother cylinders.

20.d. Thermal efficiency describes how well the engine converts the heat produced dur-ing combustion into usable power.

ADDITIONAL TEACHING HINTS

Demonstrate power balance testing, then evaluate the engines condition.Have the students identify their family vehicles as to engine type, valve train,camshaft location, and cylinder arrangement.

TECH MANUAL

The following procedures are included in Chapter 8 of the Tech Manual:

1. Performing a cylinder compression test.

2. Performing a cylinder leakage test.

3. Measuring engine oil pressure.

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ANSWERS TO TECH MANUAL REVIEW QUESTIONS

1. An engines compressions ratio expresses the decrease in the volume of the cylinderas the pistons move from BDC to TDC. The pressure of the mixture changes propor-tionally with the change in volume.

2. An engines displacement is the total volume of all of the engines cylinders.

3. A VIN gives the year, make, model, country of origin, engine size, and serial numberof the vehicle.

4. Ring noise5. Ridge noise6. Loose crankshaft thrust bearing7. Separate intake and exhaust camshafts allow the engineering of more flexibility in the

duration of the intake and exhaust valve duration.8. c9. The computer makes adjustments to the fuel and ignition systems of the vehicle to

match the temperature at which it is operating. Therefore, if the computer senses thatthe engine is hot, it will make adjustments to maintain the present temperature or tocool it down, even when the engine may need to become hotter. The end result maybe poor driveability and fuel economy.

10. Look for air leaking from the throttle body, tailpipe, or crankcase, and for air bubblesin the radiator.

11. a. loss of performanceb. excessive engine noisec. poor starting

12. a. low oil levelb. oil dilutionc. worn oil pumpd. worn main bearings

13. Carbon buildup on the piston and combustion chamber may cause an increase in com-

pression ratio; therefore, the compression pressure readings may seem normal in spiteof the fact that the cylinder is not properly sealed.14. Remove the air cleaner.15. Usually 6 or 7 revolutions or 4 compression strokes

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37

CHAPTER OVERVIEW

This chapter instructs the student in engine removal and disassembly of the cylinder headand cylinder block. Identification and cleaning of engine parts and crack detection andrepair are explained in depth.

CHAPTER OBJECTIVES

Prepare an engine for removal.Remove an engine from an FWD and an RWD vehicle.Describe how to disassemble and inspect an engine.Name the three basic cleaning processes.Identify the types of cleaning equipment.Describe the common ways to repair cylinder head cracks.


I. Removing an EngineA. FWD Vehicles

1. Removing the Engine Through the Hood Opening2. Removing the Engine from Under the Vehicle

B. RWD VehiclesHint: Divide the students into several groups. Have them find the procedure

for removing an engine from several types of vehicles such as an FWD vanand an RWD light truck in the service manuals. Compare and discuss thedifferences as a class.

II. Engine Disassembly and InspectionA. Cylinder Head RemovalB. Cylinder Head DisassemblyC. Cylinder Block Disassembly

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III. Cleaning Engine PartsA. Types of Soil Contaminants

1. Water-Soluble Soils2. Organic Soils

(a) Petroleum By-Products(b) By-Products of Combustion

(c) Coatings3. Rust4. Scale

B. Cleaning with Chemicals1. Chemical Cleaning Machines

(a) Parts Washers(b) Soak Tanks(c) Hot Spray Tanks

C. Thermal CleaningD. Abrasive Cleaners

1. Abrasive Cleaning Methods(a) Abrasive Blaster(b) Parts Tumbler(c) Vibratory Cleaning(d) Cleaning by Hand

E. Alternative Cleaning Methods1. Ultrasonic Cleaning2. Citrus Chemicals3. Salt Bath

Hint: Show the labels and MSDS for the chemicals used in the lab anddiscuss how to safely store and use them.

IV. Crack Detection and RepairA. Furnace Welding Crack Repairs

B. Repairing Aluminum Heads1. Cracks Between the Valve Seat Rings2. Cracks Coming from the Coolant Passages3. Cracks Across the Main Oil Galley4. Detonation Damage5. Meltdown Damage6. Coolant-related Metal Erosion

Hint: Arrange a field trip to a local machine shop.C. Tungston Inert Gas (TIG) Welding


1. All electronic and fuel injection parts should be covered with plastic bags during steamor other cleaning procedures to avoid direct contact with steam, water, or other clean-ing agents. EPA regulations should always be followed.

2. Wear protective gloves and goggles when using chemical cleaners.3. False.4. The best method for repairing cracked cast-iron heads is furnace welding by a

specialist.5. The preferred method of welding damaged aluminum cylinder heads is TIG welding.6. True.

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7. a. A crane is the correct equipment to use.8. a. Measure valve stem height before removing the valves. Removing carbon deposits

is done after the head is disassembled.9. a. The pushrods and rocker arms should be kept in order to aid in diagnosing valve-

related problems. The cylinder head bolts should be loosened one or two turns begin-ning in the center and working outward.

10. b. The buildup of minerals and deposits is called scale.11. c. Hydrocarbon based solvents are both toxic and flammable.12. d. Neither technician is correct. Of the two types of abrasive media, shot is round

and is used for surface peening, and grit is angular and used for aggressive cleaningjobs.

13. d. When a crack is found in the main oil gallery, it is recommended that the castingbe replaced.

14. a. Ultrasonic cleaning uses high-frequency sound waves to loosen dirt particles.15. b. Do not use a fast cooling rate. Rapid cooling causes internal stress and distortion.

Use water or shot blasting to remove ash deposits after thermal cleaning.16. d. Parts must be dry and grease-free before abrasive cleaning for best results.17. c. Both technicians are correct. The choice of cleaning methods depends on the com-

ponent to be cleaned, and sometimes it is best to clean by hand with soap and water.18. d. There is no particular order to loosening connecting rod cap bolts.19. a. Use at least four bolts to mount an engine block to an engine stand.20. c. Both technicians are correct. Small surface cracks between valve seats can be

peened, and cracks to coolant passages should be repaired by TIG welding.


Disassemble a cylinder block in the shop.Display samples of soil contaminants for students to view.Demonstrate chemical, abrasive, or some other cleaning method.Use and review all MSDSs for the shop chemical cleaning agents.

Show how disassembled engine parts should be organized.


1. Negative2. File away the excess metal on the tip before pushing the valve out of the guide.3. Label both sides of each connection to aid reassembly.4. To prevent head warpage and to ensure a good seal

TECH MANUAL


1. Preparing engine for removal.

2. Removing and disassembling the cylinder head.3. Removing cylinder ring ridge.

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5. Reverse the procedure for tightening the bolts.6. a7. 1.5 times the bolt diameter8. b9. Chemical, thermal, by hand with soap and water, abrasives, vibrations, ultrasonic, and

salt bath

10. With your fingernail

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41

CHAPTER OVERVIEW

This chapter discusses the cylinder block, crankshaft, crankshaft bearings, connectingrods, pistons and rings, oil galley, core plugs, flywheel, and harmonic balancer, focusingattention on the design and function of these essential parts.

CHAPTER OBJECTIVES

List the parts that make up a short block and briefly describe their operation.Describe the major service and rebuilding procedures performed on cylinderblocks.Describe the purpose, operation, and location of the camshaft.Describe four types of camshaft drives.Inspect the camshaft and timing components.

Describe how to install a camshaft and its bearings.Explain crankshaft construction, inspection, and rebuilding procedures.Explain the function of engine bearings, flywheels, and harmonic balancers.Explain the common service and assembly techniques used in connecting rod andpiston servicing.Explain the purpose and design of the different types of piston rings.Describe the procedure for installing pistons in their cylinder bores.


I. Cylinder Block

A. Lubrication and CoolingB. Core PlugsC. Cylinder Sleeves

II. Cylinder Block ReconditioningA. Deck FlatnessB. Cylinder WallsC. Cylinder Bore Inspection

1. Taper2. Out-of-Roundness

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D. Cylinder Bore Surface Finish1. Cylinder Deglazing2. Cylinder Boring3. Cylinder Honing

E. Lifter BoresF. Checking Crankshaft Saddle Alignment

G. Installing Core Plugs1. Disc- or Dished-Type2. Cup-Type3. Expansion-Type

Hint: Show examples of each type of plug and describe their properuses.

III. CamshaftA. Timing Mechanisms

1. Gear Drive2. Chain Drive3. Belt Drive

B. Valve Lifters1. Operation of Hydraulic Valve Lifters

C. Camshaft BearingsD. Balance Shafts

IV. Inspection of Camshaft and Related PartsA. Timing ComponentsB. LiftersC. Camshaft

V. Installing the Camshaft and Related PartsA. Camshaft BearingsB. Camshaft

VI. Crankshaft

A. Vibration DamperB. FlywheelHint: Show students different crankshaft configurations. Show both forgedand cast crankshafts.

VII. Crankshaft Inspection and RebuildingA. Crankshaft ReconditioningB. Checking Crankshaft StraightnessC. Flywheel InspectionD. Crankshaft BearingsE. Bearing MaterialsF. Bearing SpreadG. Bearing Crush

H. Bearing Locating DevicesI. Oil GroovesJ. Oil HolesK. Oil ClearanceL. Bearing Failure and Inspection

Hint: Show students a variety of damaged and worn bearings. Discuss thecauses of the failures. Have students look up crankshaft specifications inservice manuals.

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VIII. Installing Main Bearings and CrankshaftA. Crankshaft EndplayB. Connecting Rod

Hint: Demonstrate the use of Plastigage and crankshaft endplaymeasurements.

IX. Piston and Piston Rings

A. Pistons1. Head or Dome2. Rings Lands3. Piston Pin

B. Piston Rings1. Compression Rings2. Oil Control Rings

X. Installing Pistons and Connecting RodsXI. Crankshaft and Camshaft Timing

A. Camshaft end PlayB. Lifters


1. Camshaft lobe wear may be measured with an outside micrometer or with a dialindicator.

2. The deck is the top surface of the block to which the cylinder head mounts.3. Maximum cylinder bore wear occurs at the top of the ring travel area.4. a. Hydraulic lifters automatically compensate for changes in engine temperature.5. Compression rings form a seal between the piston and the cylinder walls using com-

bustion pressure to force the ring against the bottom edge of the ring groove.6. b. Aluminum pistons are most commonly used in automotive engines.

7. d. All of the above are true about core plugs.8. a. Cylinder out-of-roundness specifications are typically 0.0015 inch (.0381 mm);

acceptable cylinder taper should be 0.006 inch (0.152 mm), not 0.010 inch(.254 mm) as stated.

9. c. Both methods may be used to check for proper alignment of the bearing oil holewith the block.

10. c. Both statements are correct. The cylinder wall surface should have a crosshatchpattern and should not be so smooth that the rings are not able to seat properly.

11. d. Neither statement is correct. The timing chain should never be forced onto thesprockets; it is unnecessary to cool the sprockets.

12. a. A cup-type core plug is installed with the flanged edges pointing outward; a dish-type plug is installed with the dished side facing outward, not inward as stated.

13. b. Bearing crush refers to each half of a split bearing being slightly greater than anexact half. Bearing spread means that the distance across the parting edges of the insertshould be slightly greater than the diameter of the bearing bore.

14. d. The connecting rod journal is also called the crank pin.15. c. An outside micrometer is used to measure for both taper and out-of-roundness.16. b. Piston ring end gaps should be staggered, and most manufacturers recommend

locations for each ring. Piston ring end gap specifications vary according to ring loca-tion, with some manufacturers specifying a larger end gap for the second ring.

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17. c. Both methods are acceptable.18. b. The cam changes rotary motion of the camshaft into the reciprocating motion of

the valves.19. c. Both statements are correct.20. c. Both cast-iron and segmented rings have slots to allow excess oil to pass through.


Measure deck warpage.Demonstrate deglazing and honing.Demonstrate a crankshaft inspection.Demonstrate how to use Plastigage on the main and rod bearings.


1. a. crankb. main bearingc. rod bearing

2. Two3. Ring expander4. Micrometer5. Dial indicator and feeler gauge

6. Before teardown is complete7. The connecting rod bolts should be covered with rubber or aluminum protectors or

guides before piston and rod assembly installation.8. A drop of anaerobic thread-locking compound9. False

10. Criss-cross pattern with lines intersecting at 50-degree angles11. Micrometer12. At least eight13. c

TECH MANUAL


1. Measuring cylinder bore.

2. Measuring crankshaft journals.

3. Measuring crankshaft endplay.

4. Installing pistons and connecting rods.

5. Measuring camshaft lobes/cam and bearing journals.

6. Installing camshaft bearings.

7. Inspecting and replacing camshaft drives.8. Testing for worn cam lobes.

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14. Warped block, misaligned crankcase housing bores15. Use a micrometer and measure the journal diameter vertically and horizontally at both

ends. Then compare measurements. If the vertical measurement is different than thehorizontal, the journal is out-of-round. If there is a difference between the ends,the journal has taper.

16. Gears, belt, chain

17. Lift is the distance the valve moves on its seat or the difference between the base cir-cle of the camshaft lobe and the nose of the lobe.

18. It is tapered to cause the rotation of the lifter in nonroller lifters19. Case hardening of the camshaft lobes is important to prevent lobe wear, because there

is a high friction load between the lobes and the valve lifters.20. Clockwise

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46

CHAPTER OVERVIEW

This chapter draws attention to the different types of combustion chamber designs andintake and exhaust valves. Additional information is given about reconditioning aluminumcylinder heads, resurfacing cylinder heads, grinding valves, valve guide reconditioning, andreconditioning of valve seats.

CHAPTER OBJECTIVES

Describe the purpose of an engines cylinder head, valves, and related valve parts.Describe the types of combustion chamber shapes found on modern engines.Explain the procedures involved in reconditioning cylinder heads, valve guides,valve seats, and valve faces.Explain the steps in cylinder head and valve reassembly.


I. Cylinder HeadII. Combustion Chamber

A. Wedge ChamberB. Hemispherical Chamber

Hint: Show examples of different combustion chamber designs.III. Intake and Exhaust Valves

A. Poppet DesignB. Valve Face

C. MarginD. Important Valve Components of Four-Stroke Engines

1. Valve Guides2. Valve Springs, Retainers, and Seals3. Valve Rotators4. Camshaft Bearings5. Pushrods

Hint: Show some failed pushrods. Explain what to look for whenexamining pushrods.

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6. Pushrod Guide Plates7. Rocker Arms

E. Multivalve EnginesF. Variable Valve Timing

1. Valvetronic SystemIV. Inspection of Cylinder Head and Valve Train

A. Timing ComponentsB. Rocker ArmsC. PushrodsD. Cam Followers and Lash AdjustersE. Retainers and KeepersF. Valve RotatorsG. Valve SpringsH. Cylinder HeadsI. Camshaft and BearingsJ. Valves

Hint: Show examples of each of the cylinder head and valve traincomponents listed. Show where to look for wear patterns.

V. Aluminum Cylinder HeadsA. Reconditioning Aluminum Cylinder Heads

VI. Resurfacing Cylinder HeadsA. Surface Finish

1. Resurfacing Machines(a) Belt Surfacers(b) Milling Machines(c) Broaching Machines(d) Surface Grinders

2. Stock Removal Guidelines(a) Combustion Chamber

(b) Compression Ratio(c) Piston/Valve Interference and MisalignmentHint: Discuss why cylinder heads may need resurfacing and therelative merits of the various resurfacing methods.

VII. Grinding ValvesVIII. Valve Guide Reconditioning

A. KnurlingB. Reaming and Oversized ValvesC. Thin-Wall Guide LinersD. Valve Guide Replacement

1. Integral Guides2. Insert Guides

Hint: Compare reaming and oversized valves with thin-walled and cast-iron inserts.

IX. Reconditioning Valve SeatsA. Installing Valve Seat InsertsB. Reconditioning Integral SeatsC. Grinding Valve SeatsD. Cutting Valve SeatsE. Machining Valve Seats

Hint: Show a valve seat insert and describe the method used to install it.

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X. Valve Stem SealsA. Installing Positive Valve SealsB. Installing Umbrella-Type Valve SealsC. Installing O-Rings

Hint: Discuss the merits of positive seals over other types.D. Valve Springs

1. Freestanding Height Test2. Spring Squareness Test3. Open/Close Spring Pressure Test

Hint: Discuss why valve springs need to be tested and the consequencesof omitting this service. Show examples of failed valve springs.

XI. Assembling the Cylinder HeadA. OHC Engines


1. If valve spring tension is too low, the valves will not be closed promptly enough and

there will be valve float at higher engine speeds.2. Valve margin is the area between the valve face and the head of the valve that allows

for some machining of the valve face, which is sometimes necessary to restore its fin-ish, and allows the valve an extra capacity to hold heat.

3. Warpage in an aluminum cylinder head is usually the result of overheating or unevencooling within the cylinder head.

4. Pushrods may be checked for straightness while installed in the engine by rotatingthem when the valve is closed and visually checking for indications of wobble. Whenthe pushrods are out of the engine, they can be checked by rolling them on a flat sur-face; a pushrod that is not straight will appear to hop. The most accurate method isby using a dial indicator. If more than 0.003 (0.076 mm) TIR is found, the pushrodshould be replaced.

5. Because knurling only restores a portion of the valve guides ID to original dimensions.The raised edges produced by knurling soon wear down, and clearances rapidlybecome excessive.

6. c. Both the valve face and the tip are resurfaced by grinding.7. c. Knurling will not restore badly worn guides to their original condition.8. When the cylinder head of an OHC engine is resurfaced, the removal of material from

the head would result in the camshaft moving closer to the crankshaft, altering valvetiming. Special shims are used to raise the camshaft by the same amount as the mate-rial removed, thus restoring valve timing.

9. d. All of the above are true.10. d. All of the above are true.11.

a. If the valve face and seat do not contact evenly, the seat should be reground usingthe same stone as was used initially to correct the condition.12. c. Both technicians are correct. Bronze valve guides retain oil better than cast-iron

guides do and they last longer, but they are more difficult to machine.13. c. Both technicians are correct. Positive valve stem seals fit tightly around the stem

and scrape excess oil off the valve as it moves up and down.14. d. If the valve margin is too small, the valve should be replaced. If the valve seat is too

high, the seat should be reground using a stone with a smaller angle to lower the seat.15. d. All of the above are true.

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16. c. Low spring pressure may allow the valve to float at higher engine speed, and exces-sive spring pressure increases valve train wear.

17. b. Broaching machines use an underside rotary cutter.18. b. Normally the desired face-to-seat contact area for exhaust valves is 3/32 inch, not

1/16 inch as stated.19. d. Quenching is the cooling of gases by pressing them into a thin area.

20. c. Both technicians are correct. The Valvetronic system does not use a throttle plate,but controls the flow of incoming air directly at the intake valves by altering their dura-tion and lift.


Demonstrate carbon removal and cleaning techniques.Check the head surface for warpage with a straightedge and feeler gauge.

Pass around a valve with a too-narrow margin.Demonstrate how to check for valve spring tensions.Check for cam bore warpage on an OHC head.Demonstrate cylinder head disassembly and reassembly.Demonstrate how disassembled cylinder head parts should be organized.


1. 1.1 to 1.752. Valve seats and coolant passages3. Lower fuel consumption and emission levels4.

At the end of the camshaft near the drive pulley, a phasing mechanism reacts to a sig-nal from the engine control computer and shifts the lobe of the camshaft in accor-dance with RPM. Phasers can be controlled either electronically or hydraulically.

5. Valvetronic system6. a. inadequate lubrication

b. valve geometry problemsc. wrong valve stem-to-guide clearance

7. Exhaust valves require more clearance.8. To allow for heat expansion (exhaust valves run hotter)

TECH MANUAL


1. Inspecting cylinder head for wear.

2. Inspecting and testing valve springs for squareness, pressure, and free height comparison.

3. Inspecting valve spring retainers, locks, and valve lock grooves.

4. Replacing valve stem seals in vehicle.5. Reconditioning valve faces.

6. Inspecting valve lifters, pushrods, and rocker arms.

7. Reconditioning valve seats.

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9. Inadequate lubrication10. Small hole gauge or telescoping gauge, and micrometer11. Stem-to-guide clearance is the difference between the smallest diameter of the stem

and the largest diameter of the valve guide.12. A valve seat runout gauge (also called a concentricity gauge) is used.13. The valve seat should be replaced by either machining a counter bore to install an

inset seat, or an integral seat should be ground cut, or machined.14. The face should be ground first.15. 0.010 in. (.254 mm) can be removed from the valve tip before it must be replaced.

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51

CHAPTER OVERVIEW

This chapter describes the functions of the components of a typical lubricating and cool-ing system. Also explained are service requirements such as oil types, oil pump inspectionand installation, and cooling system inspection and service.

CHAPTER OBJECTIVES

Name and describe the components of a typical lubricating system.Inspect, service, and install an oil pump.Describe the purpose of a crankcase ventilation system.Explain oil service and viscosity ratings.List and describe the major components of the cooling system.Describe the operation of the cooling system.Describe the function of the water pump, radiator, radiator cap, and thermostat in

the cooling system.Test and service the cooling system.


I. LubricationA. Oil types

1. ISLAC Oil Ratings2. Synthetic Oils

B. Oil ConsumptionHint: Show several oil containers and explain how to find and identifythe different ratings. Discuss the merits of using synthetic and synthetic

blended oils.II. Lubricating Systems

A. Oil PumpB. Oil Pump PickupC. Oil Pan or SumpD. Pressure Relief ValveE. Oil FilterF. Engine Oil Passages or GalleriesG. Engine Bearings

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H. Oil Pressure IndicatorI. Oil Seals and GasketsJ. Dipstick

III. Oil PumpA. Types of Oil Pumps

1. Rotor-type

2. Gear-typeB. Pressure Regulation

IV. Oil Pump Inspection and ServiceHint: Show several different types of oil pumps. Show how to disassemble andexamine them. Show the areas where wear is most likely to be found.

V. Installing the Oil PumpVI. Cooling Systems

A. Coolant1. Chemical Treatments

B. Thermostat1. Effects on Driveability

C. Water PumpD. Radiator

1. Oil CoolerE. Radiator Pressure Cap

1. Expansion TankF. Hoses

1. Water Outlet2. Water Jackets

G. Hose ClampsH. Belt DrivesI. Cooling Fans

1. Electric Cooling Fans

J. Temperature Indicators1. Temperature SensorsK. Heater System

VII. Cooling System ServicingA. Coolant ConditionB. Testing the Cooling System for LeaksC. Repairing RadiatorsD. Testing the Radiator Pressure CapE. Testing the ThermostatF. Checking and Replacing HosesG. Water Pump Service

1. Replacing the Water Pump

H. Checking Fans and Fan ClutchesI. Checking Belts

1. Belt Replacement2. Belt Tension

J. Coolant Recovery and Recycle SystemK. Flushing Cooling SystemsL. Refilling and Bleeding

Hint: Show examples of various hose and belt failures. Cut an upper radiatorhose lengthwise so that students can see how hoses begin to deteriorate from

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the inside first. Show a hose with ECD. Demonstrate testing a thermostat foropening temperature and for sticking.


1. Increase the difference between the temperature of the coolant and the outside airflowing through it.

2. The closed system type radiator cap is the one that is most commonly used.3. To determine whether the water pump is creating good circulation, warm up the

engine and run it at idle speed. Squeeze the upper radiator hose with one hand andaccelerate the engine with the other. If a surge of coolant is felt at the hose, the pumpis circulating coolant.

4. The oil pump is typically driven by the crankshaft or camshaft.5. The pressure regulator valve6. d. All of the above7. b. Oil pressure is dependent upon oil viscosity. Rotor type pumps produce greater

flow than gear pumps.8.

c. Both technicians are correct. Oil filters may be equipped with a check valve, andthe input side of the oil pump has a filter screen to prevent large particles from enter-ing the pump.

9. Electrochemical degradation (ECD) is the primary cause of hose failures.10. False. The fan clutch operates only when the engine and radiator are heated up and

not as stated.11. c. Both technicians are correct. A straightedge and feeler gauges are used to deter-

mine pump cover flatness, and an outside micrometer is used to measure the diam-eter and thickness of an oil pump outer rotor.

12. c. API oil classifications are grouped into S classifications (standard) for passengercars and C classifications for diesel (compression ignition) engines.

13. b. Higher viscosity oils receive higher rating numbers. The Society of Automotive

Engineers (SAE) establishes viscosity ratings, not API as stated.14. b. Each pound of pressure on engine coolant raises the boiling point about 3F (16C).15. c. Automotive water pumps are usually belt driven from the crankshaft.16. d. The inner rotor to housing dimension is not measured, but the clearance between

the outer rotor and housing is checked with feeler gauges.17. d. Premature bearing and bushing failure in water pumps, generators, and power

steering pumps results from excessive belt tension, not insufficient tension as stated.18. c. A thermostat must be fully open when it is 20F (6.6C) above its opening

temperature.19. b. An air leak on the suction side of an oil pump may cause the oil to become aerated.20. b. When installing an oil pump, submerge it in clean oil and rotate it by hand until

oil emerges from the discharge port.

TECH MANUAL


1. Servicing and installing oil pump and oil pan.

2. Inspecting, replacing, and adjusting drive belts and pulleys.

3. Cleaning, inspecting, testing, and replacing electric cooling fans and cooling system-related temperature sensors.

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Examine and discuss an oil pump pressure valve.Examine an oil pressure system, pointing out the location of sending units, oil lines,and gauges.Completely inspect several types of oil pumps according to manufacturers

recommendations.Examine the various types of radiator core constructions.Pressure test the cooling system for leaks.


1. a. ambient temperatureb. stuck pressure regulating valvec. high-viscosity oil

2. Oil pumps are driven, directly, indirectly, and by the camshaft or by a gear at the frontof the crankshaft.

3. Air leaks on the inlet side of the pump can cause the pressure relief valve to hammerback and forth, the oil can become aerated and foamy, and engine wear can occur dueto marginal lubrication.

4. If any part of the housing is scored or noticeably worn, replace the pump as anassembly.

5. In newer engines, the baffle assembly is used to restrict oil movement in the oil sump.6. Using a thermostat with a different opening temperature than was originally installed

on a computerized engine will cause many driveability problems including poor gasmileage and excessive emissions.

7. A faulty head gasket and a cracked head or cylinder8. True9. The source of an external coolant leak can found by a thorough visual inspection or

the use of a dye penetrant.10. Wait for 15 to 20 minutes and check for a pressure drop on the tester gauge.11. False12. False13. c14. c15. c

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55

CHAPTER OVERVIEW

This chapter describes the gaskets, sealants, adhesives, and fasteners needed to correctlyseal an engine. Improvement in sealing technologies is introduced in this chapter.

CHAPTER OBJECTIVES

Explain the purpose of the various gaskets used to seal an engine.Identify the major gasket types and their uses.Explain general gasket installation procedures.Describe the methods used to seal the timing cover and rear main bearing.Reassemble and engine including core plugs, bearings, crankshaft, camshaft,

pistons, connecting rods, timing components, cylinder head, valve traincomponents, oil pump, oil pan, and timing covers.Explain the ways to prelubricate a rebuilt engine.Reinstall an engine and observe the correct starting and break-in procedures.


I. Torque PrinciplesA. ElasticityB. Torque-to-yield (T-T-Y)C. Thread Repair

II.GasketsA. Gasket MaterialsB. General Gasket Installation ProceduresC. Cylinder Head Gaskets

1. Bimetal Engine RequirementsD. Manifold GasketsE. Valve Cover GasketsF. Oil Pan Gaskets

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III. Adhesives, Sealants, and Other Chemical Sealing MaterialsA. AdhesivesB. Sealants

1. General-Purpose Sealants2. Flexible Sealants3. Silicone Formed-in-Place Sealants

4. Anaerobic Formed-in-Place SealantsC. Antiseize Compounds

Hint: Discuss the importance of using oxygen sensorsafe RTV and antiseizecompounds.

IV. Oil SealsA. Timing Cover Oil SealsB. Rear Main Bearing Oil SealsC. Other Seals

Hint: Discuss oil seal burning and emphasize the importance of lubricatingthe oil seal lip.

V. Engine ReassemblyA. Installing the Cylinder Head and Valve Train

1. Torque Angle GaugeB. Timing BeltsC. Adjusting ValvesD. Final Reassembly Steps

1. Install the Timing Cover2. Install the Vibration Damper3. Install the Valve Cover4. Install Oil Pan5. Install Intake Manifold6. Prelubrication7. Install the Thermostat and Water Outlet Housing

8. Install Exhaust Manifold9. Install Flywheel or Flex Plate10. Install Clutch Parts11. Install Torque Converter12. Install Motor Mounts

VI. Installing the EngineA. Installing the Engine into a FWD VehicleB. Installing an Engine in a RWD VehicleC. Starting ProcedureD. Break-In ProcedureE. Relearn Procedures


1. True.2. A bolt that has been stretched to its yield point will not return to its original length.3. Cylinder head, exhaust manifold, and some intake manifold gaskets4. On the threads of bolts exposed to fluids5. Whether they cure in the presence or absence of air, and their gap filling ability

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6. b. Most cylinder head bolts are tightened in a sequence that begins in the center, noton one end as stated.

7. True.8. b. Torque-to-yield bolts should not be reused. Head bolts that pass through a coolant

passage should be coated with a nonhardening sealer.9. c. Both procedures are accepted.

10. c. Soft gaskets are used in both applications11. c. Gaskets should not be reused. Silicone gasket material may be used to replace con-

ventional paper, cork, or cork/rubber gaskets when necessary.12. d. The cylinder head gasket does not meter oil onto the cylinder walls.13. False. When the rocker arm is torqued, the plunger in the lifter is properly positioned;

hand priming is not recommended and could damage valve train components.14. d. Graphite is neither an anaerobic nor an RTV. It is a lubricant.15. c. Damaged threads on a bolt may sometimes be repaired using a tap and die set. If

the head of the bolt is not against the surface after it reaches the proper torque, it istoo long and should be removed and replaced with a shorter bolt or have a washerplaced under the head of the bolt. The bolt hole should first be reinspected for debristhat may have fallen in during the cleaning process, and a cleaning tap should be usedto clear the hole.

16. d. All of the above17. b. Rear main seals are not made of RTV.18. a. Aluminum expands at a greater rate than cast iron, not as stated by Technician B.19. d. Neither technician is correct. Neither technique is recommended. After the engine

has started, it should be run at about 1,500 rpm until it reaches operating tempera-ture, not at idle speed as stated by Technician A. During the test drive, the vehicleshould only be accelerated from 30 mph (48 km/h) to 50 mph (80 km/h) at least tentimes at full throttle. Some manufacturers of late model engines no longer recommenda break-in procedure.

20. c. Run a nut over the bolts threads by hand, and if any binding occurs you should

discard the bolt, not tap the nut as stated.


Examine various metric and UNS bolts. Identify the size of the bolt head, and thediameter, length, and thread pitch of each bolt.Demonstrate impression testing.Demonstrate RTV, antiseize, Loctite, and other gasket sealers.Demonstrate engine prelubrication processes.Demonstrate torque-to-yield bolt tightening.Demonstrate valve lash adjustment.

TECH MANUAL


1. Applying RTV silicone sealant.

2. Adjusting valves on an OHC engine.

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1. True.2. If dry nuts are reused, increased thread galling will result each time the nuts are reused

at the same torque.3. Thread stripping

4. Hard gaskets are made of steel, stainless steel, copper, or a combination of metals witha compound sandwiched between the metals. A soft gasket is made of cork, rubber, acombination of cork and rubber, or rubber-coated steel, paper, or other compressiblematerials.

5. Aerobic6. In the absence of air or free oxygen7. A T-T-Y bolt is tightened just barely into a yield condition. This stretches the bolt to

its near maximum amount without distorting it, providing for maximum clampingability.

8. Once the engine is bolted to its motor mounts9. Tighten to the proper torque and in the order specified by the manufacturer

10. a. rocker arm with adjustable pivotsb. adjustable pushrodsc. rocker arms with adjustable screwsd. adjustable cam followers

11. Make a test run at 30 mph (48 km/h) and accelerate at full throttle to 50 mph (80km/h). Repeat the acceleration cycle from 30 mph to 50 mph (48 km/h to 80 km/h)at least ten times.

12. True13. d14. Engine will overheat15. The relearn procedure involves operating the vehicle in a prescribed manner so the

computer learns the present condition of the vehicle. Always follow the manufactur-

ers relearn procedures as outlined in the service manual.

SECTION 2

Answers to ASE Prep Test Questions

1. c 6. a 11. c 16. a2. c 7. c 12. b 17. c3. a 8. b 13. b 18. b4. c 9. c 14. c 19. b5. a 10. a 15. b 20. b

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