单项选择题The satisfactory operation of diesel engine exhaust valves usually depends on()

A.the proper back pressure
B.the cooling water temperature
C.correct timing and proper seating
D.accurate metering and the exhaust temperature


您可能感兴趣的试卷

你可能感兴趣的试题

1.单项选择题If an auxiliary diesel engine frequently stalls, the trouble may be caused by ()

A.low exhaust back pressure
B.air in the fuel system
C.gasket blow-by or leakage
D.incorrect assembly of idler springs

3.单项选择题The exhaust gases in a supercharged two-stroke/cycle diesel engine are expelled from the cylinder by ()

A.pumping action of the piston
B.pressure of the fuel charge
C.vacuum developed in the manifold
D.pressure of the fresh air charge

4.单项选择题Which of the listed items should be secured before performing any maintenance on a solenoid operated air start valve?()

A.Electric power and starting air
B.Lube oil standby pump and control air
C.Hydraulic switch and engage jacking gear
D.Motor drain and pneumatic control system power

6.单项选择题Which of the following problems can occur if you continually fail to drain off condensate from a starting air receiver?()

A.Corrosion and eventual failure of the tank
B.Gumming of the tank relief valves
C.Immediate failure of components downstream of the compressed air system
D.Boiling of the water oil mixture as pressure is reduced

7.单项选择题During the valve overlap period, the exhaust pressure of a turbochargers, four-stroke/cycle diesel engine must be less than the intake manifold pressure to ensure ()

A.effective cylinder scavenging and cooling
B.constant pressure from the turbochargers
C.cooler operation of the exhaust system
D.effective constant pressure for turbocharger operation

9.单项选择题When the normal compression ratio of a diesel engine is not very high, misfiring at light loads may be caused by ()

A.overloading the engine
B.low exhaust valve lift
C.excessive cylinder cooling
D.insufficient mechanical clearance

10.单项选择题In a two-stroke/cycle diesel engine, the exhaust gases are expelled from the cylinder by the()

A.exhaust manifold
B.valve bridge
C.pressure of the fresh air charge
D.valve adjusting gear