更多"The intake valves in a diesel engin"的相关试题:
[单项选择]A restricted air intake to a diesel engine may result in the engine （）.
A. failing to reach rated speed
B. knocking under maximum load
C. hunting or surging under light load
D. overspeeding and running away
[单项选择]In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low alloy steels because （）.
A. the beveled edges of the intake valves provide for serf-centering during seating
B. intake valves utilize stellite-coated valve seat inserts which reduce wear
C. the volume of air passing through intake valves is less than the volume of air passing through exhaust valves
D. intake valves are less affected to the corrosive action of exhaust gases
[单项选择]Intake air flow from a diesel engine turbocharger is directly proportional to engine（）
A. exhaust gas pressure
B. exhaust gas temperature
C. speed
D. load
[单项选择]Cooling the intake air supplied to a diesel engine will （）.
A. reduce mean effective pressure
B. decrease average compression pressure
C. decrease air charge density
D. increase power output
[单项选择]Worn diesel engine intake valve guides can result in （）
A. increased engine breathing efficiency
B. excessive valve lash
C. excessive lube oil consumption
D. lower than normal fuel consumption
[单项选择]Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to （）
A. provide added wear protection against today’s corrosive quality of fuel
B. increase overall valve strength due to the high gas pressures
C. assist in dissipating heat due to the extreme operating temperatures
D. reduce the overall weight of the valve thus helping eliminate valve spring surge and hammering
[单项选择]An indication of a diesel engine air intake being partially clogged, is （）.
A. low firing pressure and low exhaust temperatures
B. low firing pressure and normal exhaust temperatures
C. high firing pressure and low exhaust temperatures
D. high firing pressure and high exhaust temperatures
[单项选择]A turbocharged diesel engine will have an intake manifold pressure（）
A. constantly decreasing as engine load increase
B. constantly increasing as the amount of supercharging increases
C. approximately equal to exhaust manifold pressure at all times
D. approximately equal to atmospheric pressure at all times
[单项选择]The timing of diesel engine air starting valves is controlled by（）
A. the air start valve timing gears and rods
B. a cylinder check valve
C. individual cams and valve gear
D. an air manifold poppet valve
[单项选择]Valves in the cylinder head of a diesel engine are opened by the direct action of the（）
A. exhaust pressure
B. valve spring pressure
C. rocker arm movement
D. wrist pin movement
[单项选择]Diesel engine air start system check valves are opened by （）
A. an air start cam
B. cylinder compression pressure
C. starting air pressure
D. valve springs
[单项选择]
In a diesel engine, exhaust valves open before the intake ports are uncovered to （）
Ⅰ.reduce pumping losses
Ⅱ.reduce back pressure
A. Ⅰonly
B. Ⅱonly
C. bothⅠand Ⅱ
D. neitherⅠnor Ⅱ
[单项选择]In a four-stroke cycle diesel engine the intake valves open （）
A. before TDC and close after BDC
B. after TDC and close after BDC
C. before TDC and close before BDC
D. after TDC and close before BDC
[单项选择]Engine coolant accumulating in the diesel engine lubricating oil can result from a （）
A. low oil pressure
B. high coolant pressure
C. leaking fuel injector
D. cracked cylinder head or liner
[单项选择]Before starting a diesel engine that has an engine driven lube oil pump, the engineer should （）.
A. open the bypass line
B. cut in the lube oil cooler
C. pressurize the lube oil system
D. top off the expansion tank
[单项选择]The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.
A. principle
B. principal
C. cause
D. case
[单项选择]Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are （）.
A. operated manually once an hour
B. operated until the engine has started
C. placed into operation only at maximum load
D. adjustable to meet lubrication requirements
[单项选择]Diesel engine mufflers accomplish noise reduction by （）
A. reducing exhaust gas velocity
B. increasing the frequency of gas vibration
C. the use of long head pipes
D. the use of zinc electrodes
