单选题In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the （）.Astarting air and fuel pumpsBpiston cooling pumpsCexhaust valvesDall of the above
单选题
In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the （）.
A
starting air and fuel pumps
B
piston cooling pumps
C
exhaust valves
D
all of the above
参考解析
解析：
暂无解析
相关考题：
单选题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of （）Aless even torqueBhigher cylinder head temperaturesCfewer power strokes per revolutionDgreater weight/size requirements
单选题In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines, （）Awide compression rings are usedBoil rings are located above the pistonCchromium plating is used on all piston ringsDoil rings are located near the bottom of the piston skirt
单选题The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speedIn maintaining this relationship, the camshaft drive causes the camshaft to rotate at（）Aone half crankshaft speed in a two-stroke cycle diesel engineBcrankshaft speed in a two-stroke cycle diesel engineCtwo times crankshaft speed in a two-stroke cycle diesel engineDone-fourth times crankshaft speed in a four-stroke cycle diesel engine
单选题The two-stroke cycle begins with the piston coming up from the bottom of its stroke, with scavenge ports in the sides of the cylinder being （）.AshutBclosingCopenedDclosed
单选题The two-stroke cycle begins with the piston coming up from the BDC, with the scavenging ports in the sides of the cylinders being （）.AopenBuncoverCcoveredDclosed
单选题In describing engine operation, what does the term “cycle” mean?（）AThe sequence of events that produce a power pulseBOne rotation of the engine crankshaftCOne stroke of a pistonDAll of the above
单选题When inspecting piston rings through the ports of a two-stroke/cycle diesel engine, black areas on the sealing surfaces are the result of （）Ainsufficient lubricationBimproper piston coolingCblow-byDoverload operation
单选题The size of the exhaust valve opening is （）Amost critical in a four-stroke cycle diesel engineBmost critical in a two-stroke/cycle diesel engineCmost critical in a four-stroke/cycle diesel engine if it is turbochargedDof equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
单选题Which of the two events listed occurs simultaneously in a two-stroke/cycle diesel engine?（）AExhaust and scavengingBScavenging and compressionCIgnition and expansionDExhaust and compression
单选题The exhaust system for a turbocharged two-stroke/cycle diesel engine functions to（）Adischarge exhaust gases and smokeBfurnish energy to the turbochargerCreduce engine room noiseDall of the above
单选题Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because （）Abearing pressure in a four-stroke/cycle acting single diesel engine is continually reversedBbearing pressure in a two-stroke/cycle single acting diesel engine is continually reversedCthe maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engineDtwo-stoke/cycle diesel engines require more complicated lubrication piping
单选题Oil control rings used in two-stroke/cycle diesel engines are located near the bottom of the piston skirt in order to （）Aincrease the liner area covered by the oil filmBmaintain an oil film on the lower liner where scuffing is prevalentCkeep excess oil away from intake and exhaust portsDhelp cushion piston skirt side thrust by providing a hydrodynamic oil wedge
单选题In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in （）.Atwo crankshaft revolutions in a two-stroke/cycle engineBtwo power strokes in a two-stroke/cycle engineCone power stroke in a two-stroke/cycle engineDtwo piston strokes in a two-stroke/cycle engine
单选题Large, two-stroke/cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the （）.Aexhaust gas temperature systemBexhaust load systemCconstant or pulse pressure systemDconstant volume system
单选题Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?（）AIn a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greaterBSome provision must be made in a two-stroke/cycle engine to keep the rings from binding in the portsCNo gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engineDThe gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine
单选题In a two-stroke/cycle diesel engine, the exhaust gases are expelled from the cylinder by the（）Aexhaust manifoldBvalve bridgeCpressure of the fresh air chargeDvalve adjusting gear
单选题If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately（）Athe same indicated horsepower as a four-stroke/cycle engineBtwice the indicated horsepower as a four-stroke/cycle engineCone half indicated horsepower as a four-stroke/cycle engineDone power stroke for every two crankshaft revolutions
单选题A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine（）Ahas little or no internal frictionBhas a lower effective compression ratioCoperates with scavenge air under a positive pressureDoperates without energy absorbing intake and exhaust strokes
单选题The two strokes of a two-stroke/cycle diesel engine are （）Apower and intakeBintake and exhaustCexhaust and compressionDcompression and power
单选题In a single acting, two-stroke/cycle, diesel generator engine, the power impulse in an individual cylinder occurs （）Aonce every crankshaft revolutionBonce every two crankshaft revolutionsConce every piston strokeDtwice every piston stoke
单选题The process of scavenging a two-stroke/cycle diesel engine serves to（）Aimprove fuel flow volumeBcool the exhaust valvesCreduce the intake air charge densityDincrease the temperature of exhaust gases
单选题The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is （）.A475 RPMB950 RPMC1900 RPMD2400 RPM
单选题For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because （）.Ait has a longer power strokeBmore air gets into the cylinder each strokeCit develops twice as many power strokes at the same speedDhigher combustion pressure is developed