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单项选择题
A.starting the engine hot
B.knurling the piston skirt
C.operating an overheated engine
D.using scuff resistant piston rings
单项选择题
A.the amount of lube oil additives increase
B.piston speeds increase
C.injection pressure decrease
D.engine speeds decrease
单项选择题
A.less piston slap and quieter running
B.increased crankshaft bearing wear
C.slightly greater piston wear
D.decreased side pressures
单项选择题
A.Liner wear is distributed equally between the upper and lower portions of the cylinder
B.Excessive liner wear causes wear between piston ring and groove
C.Excessive, but uniform liner wear will not cause wear between piston ring and groove
D.Liner wear is normally greatest in the middle of the cylinder
单项选择题
A.alternation of side thrust
B.a breakdown of the lube oil film on the cylinder wall
C.worn piston boss piston pin bearings
D.fluctuating gas pressure in the combustion space
单项选择题
A.hard starting
B.excessive fuel consumption
C.loss of power
D.all of the above
单项选择题
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
单项选择题
A.Excessive piston to liner clearance
B.The underside of the piston crown being excessively dirty lowering the rate of heat transfer
C.Faulty nozzle spray
D.All of the above
单项选择题
A.improve skirt lubrication
B.allow for expansion
C.transmit forces evenly
D.improve the piston seal
单项选择题
A.Hard alloy steel construction
B.Beveled edges on the valve head
C.Low alloy steel construction
D.Poppet type design