Advanced Auto Tech ASE A ­ 1 Test Preparation Engine Upper End Theory & Service Torque­to­yield bolts stretch to their yield point when tightened and should not be reused. True or False The sealing lip & spring on an oil seal should face toward the fluid being sealed. True or False Intake manifolds can be made of plastic or aluminum. True or False Exhaust manifolds are typically steel or cast iron. True or False Oil pumps should be primed with high temperature wheel bearing or chassis grease to prevent dry starts. True or False Variable valve timing is done through hydraulic actuators on the cam sprockets & PCM­controlled solenoids that switch oil flow. True or False Lift of a camshaft lobe is determined by subtracting base diameter from the overall lobe height. True or False OHC timing belts have a recommended replacement interval or service interval to prevent slippage or breakage which can bend valves. (freewheeling vs. interference valve train) True or False The positive aspect of belts is that they are smooth and quiet and the disadvantage is they periodically need to be replaced. The mileage interval for replacing most belts is from 60,000‐105,000 miles. Some water pumps on OHC engines are driven by the timing belt. True or False Valve Seats, valve guides, & valves themselves can all be serviced by complete replacement. True or False An “interference engine” will collide the valves with the piston if the timing belt slips. True or False Interference fit of valves indicates a ½ º to 1 ½ º difference between face & seat angles. (usually 1º) True or False 45° 46° If a warped head is milled or a warped block is decked, compression ratio will increase. True or False Which precision measuring tools are used in combination to check cylinder head flatness or warp? After grinding valve faces & seats, valve spring installed height: A. Increases B. Decreases C. Stays the Same After grinding valve faces & seats, valve stem height: A. Increases B. Decreases C. Stays the Same After adding valve spring shims, valve spring installed height: A. Increases B. Decreases C. Stays the Same After adding valve spring shims, valve spring free length: A. Increases B. Decreases C. Stays the Same What is the compression ratio of an engine with a 500 cc cylinder & a 50 cc combustion chamber? 500 ÷ 50 = __ What is the compression ratio of an engine with a 500 cc cylinder & a 40 cc combustion chamber? 500 ÷ 40 = __ What is the compression ratio of an engine with a 500 cc cylinder & a 52.5 cc combustion chamber? 500 ÷ 52.5 = __ For a 46º valve seat, a typical topping angle would be: A. 30º or 31º B. 60º C. 15º What must be done to remove a valve with a mushroomed tip from a cylinder head? Name 3 methods for crankshafts to drive camshafts: Name the parts of the valve A. C. A = Valve Margin C = Valve Face B. B = Valve Stem Name the valve train parts: A = Valve Keepers A. B. B = Valve Spring Retainer C = Valve Seal D = Valve Guide C. D. Measure a valve guide & a valve stem, then determine clearance ” Valve Guide Valve Stem Valve Guide Valve Stem Measure a valve guide & valve stem, then determine clearance mm Valve Guide Valve Stem Closer together coils of a valve spring designed to prevent float, flutter, and bounce of the valve as it slams shut into the seat A. Thin­Wall Liners B. Spring Shims C. Dampening Coils D. Lifter Shims Repair for a worn valve guide consisting of a thin bronze bushing that gets press­fit into a reamed out guide restoring original I.D. A. Thin­Wall Liner B. Spring Shims C. Dampening Coils D. Lifter Shims Style of valve lifter that is supplied with pressurized oil in an effort to maintain zero lash & provide quiet operation A. Roller Lifter B. Valve Rotator C. Mechanical Bucket Lifter D. Hydraulic Lifter Crack detection method commonly used on non­ferrous materials A. Dye Penetrant B. Magnafluxing ® C. Plastigauge® D. X­Ray Inspection OEM method of cancelling fuel & compression on cylinders when not needed in an effort gain fuel economy A. Displacement on Demand® B. Roller Hydraulic Lifter C. Hydraulic Bucket Lifter D. Valve Rotator Exhaust valve train component that prolongs seat & face life by wiping them clean through rotation of the valve A. Valve Rotator B. Oil Squirter C. Dampening Coils D. Lifter Shims Name for the distance between the valve stem tip and the component that moves it – rocker arm, follower, tappet, lifter, etc. A. Valve Clearance B. Valve Train Play C. Valve Lash D. A & C Parts that are used to adjust valve spring installed height after cutting seats & faces A. Bucket Lifter Shims B. Valve Spring Shims C. Valve Rotators D. Valve Tip Caps Devices to provide a pressurized stream of lubrication to critical friction areas A. Oil Squirter B. Valve Rotator C. Roller Lifter D. Chain Guide Style of valve lifter using a wheel against the camshaft lobe in an effort to reduce valve train friction A. Oil Squirter B. Valve Rotator C. Roller Lifter D. Chain Guide A nylon­coated rail in which timing chains ride, preventing chain slack & chain deflection as well as quieting chain operation A. Oil Squirter B. Valve Rotator C. Roller Lifter D. Chain Guide A replaceable part of very accurate thickness used to adjust valve lash on a valve train equipped with mechanical ‟bucket lifters” A. Lifter Shim B. Valve Spring Shim C. Valve Stem Cap D. Ball Pivot & Nut Valve Guide Measures 0.312” 0.312” 0.310” 0.002” Valve Stem Measures 0.310” Valve Guide Measures 6.00 to 6.01 mm 6.00 mm 5.96 mm 0.04 mm Valve Stem Measures 5.95 to 5.96 mm .