produce a scavenging effect in the combustion space
equalize cylinder and exhaust manifold pressures
alleviate the difference in valve size between the intake and exhaust
flush out condensate that collects after each compression stroke
第1题：
one half crankshaft speed in a two-stroke cycle diesel engine
crankshaft speed in a two-stroke cycle diesel engine
two times crankshaft speed in a two-stroke cycle diesel engine
one-fourth times crankshaft speed in a four-stroke cycle diesel engine
第2题：
most critical in a four-stroke cycle diesel engine
most critical in a two-stroke/cycle diesel engine
most critical in a four-stroke/cycle diesel engine if it is turbocharged
of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
第3题：
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.
A.The direction of pressure on the journal in four-stroke engine is continuously
B.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
C.four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
D.Low-stroke engines usually consume less lube oil than four-stroke engines
第4题：
bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversed
bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversed
the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine
two-stoke/cycle diesel engines require more complicated lubrication piping
第5题：
discharge exhaust gases and smoke
furnish energy to the turbocharger
reduce engine room noise
all of the above
第6题：
supercharging
scavenging
turbulence
swept volume charging
第7题：
The direction of pressure on the journal in four-stroke engine is continuously
positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
Low-stroke engines usually consume less lube oil than four-stroke engines
第8题：
If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two stroke/cycle diesel engine will develop approximately
A.the same indicated horsepower as a four-stroke/cycle engine
B.twice the indicated horsepower as a four-stroke/cycle engine
C.one half the indicated horsepower as a four-stroke/cycle engine
D.one power stroke for every two crankshaft revolutions
第9题：
improper venting of the cooling system
carrying the expansion tank water level too high
a totally clogged impeller in the cooling water pump
an incorrectly set cooling system temperature control
第10题：
during the valve overlap period
with only the exhaust valve open
at a pressure below atmospheric
without cooling the cylinders or pistons