CM Advanced Ch.3 Flashcards
What is a unit for measuring work per unit of time?
Horsepower
One horsepower is equivalent to how many foot-pounds of work per minute?
33,000
What is the theoretical power that an engine would deliver if all fictional losses were eliminated?
Indicated horsepower
What is the actual amount of power that an engine can deliver at a certain speed with a wide-open throttle?
Brake horsepower
What may be used to test an engine that has been removed from the vehicle it drives?
Engine dynometer
What can give a quick report on engine conditions by measuring output at various speeds and loads?
Chassis dynometer
What is the difference between indicated horsepower and brake horsepower?
Friction horsepower
There are two kinds of horsepower commonly used by manufacturers in rating the power of construction vehicles: drawbar and what other type of horsepower?
Belt
The three basic factors that affect an internal combustion engines power are as follows: COMPRESSION, IGNITION, and what else?
CARBURETION
As a rule, what percent of the output of an engine is lost for every 1,000-foot increase in elevation above sea level?
2 1/2
Engineers will deduct as much as 1% for each 10°F rise in the intake air temperature above a “normal” temperature of what?
70°F
Low oil pressure usually indicates what?
Worn engine bearings
Valve and tappet noise is a regular clicking sound that increases in intensity as the engine speed increases. The cause is usually excessive what?
Valve clearance
What may be detected by a hollow, bell like knock and is due to the rocking back and forth of the piston in the cylinder?
Piston slap
What is a heavy, dull, metallic knock that is noticeable when the engine is under load or accelerating?
Crankshaft knock
Four of the most widely used testing instruments are the cylinder compression tester, vacuum gauge, cylinder leakage tester, and what else?
Tachometer
The compression pressure in the different cylinders of an engine may vary as much as how many pounds?
20
Normal compression readings for gasoline engine cylinders are usually what psi or slightly higher?
100
When a test is made at an elevation of 1,000 feet or less, an engine in good condition, idling at a speed of about 550 rpm, should give a steady reading of from 17 to how many inches on the vacuum gauge?
22
What is a speed-indicating instrument that measures the rpm of a rotating shaft?
Tachometer
What may be caused by gum or carbon deposits, worn valve guides, a warped valve stem, insufficient oil, cold engine operation, or overheating?
Sticking valves
What may be caused by a sticking valve, insufficient valve taller clearance, a distorted seat, overheated engine, lean fuel-air mixture, pre-ignition, detonation, or valve seat leakage?
Valve burning
What may occur by valve overheating, detonation, excessive tappet clearance, seat eccentric to stem, cocked spring or retainer, or scratches on the stem caused by improper cleaning?
Valve breakage
What may be caused by excessive tappet clearance, dirt on the face, or distortion?
Valve face wear
What may be produced by gum in the fuel, a rich fuel mixture, poor combustion, worm valve guides, dirty oil, or the use of a wrong oil?
Valve deposits
The first indication of a faulty hydraulic valve lifter is what type of noise?
Clicking
The first step in servicing valves after they have been removed from the engine is to rid them of what?
Carbon
Two general types of valve seat grinders are in use. One is a concentric grinder; the other, is what type of grinder?
Eccentric
Before installing a new valve seat insert, chill it for how many minutes in dry ice or by any other chilling method?
15
There are two types of valve lifters: the solid type and what other type?
Hydraulic
The relationship between the camshaft and the crankshaft determine the what?
Valve timing
Most modern engines have main and connecting rod bearings of what type, which can be replaced without removing the crankshaft?
Precision-insert
Journals that are tapered or out of round more than what amount must be regrounded?
.003
What is a plastic material that is flattened by pressure?
Plastigage
If the crankshaft is locked or drags noticeably after the bearing cap has been replaced and tightened, then the bearing clearance is less than the thickness of the feeler stock. If it does not tighten or drag, place an additional thickness of feeler stock on top of the first and again check the ease of crankshaft movement, clearance normally should be about what?
.002 inch
There are two methods of refinishing cylinders: what are they?
Honing and boring
What is used sometimes to “break” or “crack” the glaze on cylinder walls when new rings are installed?
Honing
After a piston has been cleaned it should be measured with what?
Outside micrometer
Upon starting the newly overhauled engine, of mo oil pressure is observed in the first how many seconds, shut the engine down and find the cause?
10 to 15
