单选题In order to keep the oil film on the cylinder liner during the running-in period, the piston rings are slightly rounded（）Aon both the external and internal top edgesBon both the external top and bottom edgesCon both the external and internal bottom edgesDon all the four edges
单选题
In order to keep the oil film on the cylinder liner during the running-in period, the piston rings are slightly rounded（）
A
on both the external and internal top edges
B
on both the external top and bottom edges
C
on both the external and internal bottom edges
D
on all the four edges
参考解析
解析：
暂无解析
相关考题：
Diesel engine blow-by is the leakage of combustion gases past the( ).A.oil rings onlyB.compression and scraper ringsC.cylinder liner sealingD.cylinder liner ring grooves
Low compression in a diesel engine could be caused byA.worn or broken cylinder liner sealing ringsB.high cooling water temperatureC.worn or broken piston ringsD.low fuel oil pressure
单选题Low compression in a diesel engine can be caused by （）Aclogged coolant passagesBa leaking cylinder head gasketClow fuel oil pressureDworn or broken cylinder liner sealing rings
单选题The rate of cylinder lubricating oil metered to each cylinder of a large low-speed main propulsion diesel engine is （）Athe same, whether at sea, or during maneuveringBadjusted during each hour of operation while at constant RPMChigher at sea than while maneuveringDlower at sea than while maneuvering
单选题The consistent burning of fuel oil with a high sulfur content in a diesel engine will result in （）Aclogged fuel injection pumpsBincreased cylinder liner wearCintake valve stem corrosionDvarnish deposit on pistons
单选题The primary purpose of oil control rings on a diesel piston is to（）Aprovide a reservoir for cylinder lubricationBpump oil into the combustion space for cylinder coolingCprevent excessive lubricating oil consumptionDallow hydraulic oil film formation on the cylinder
单选题The film of oil between the rings and the liner is not only essential for the lubrication but also plays an important part in achieving （）.Aan oil sealBremoving heatCa gas sealDcooling the piston
单选题In addition to lubricating, cylinder oil assists in forming a gas seal and contains （） which clean the cylinder liner.AadditivesBwaterCgreaseDacid solution
单选题Improper cooling of a diesel engine cylinder liner due to the accumulation of scale deposits may cause （）.Alow compression pressureBincreased piston wearCincreased cylinder lube oil consumptionDpoor contact between compression rings and liner
单选题The diameter of a piston is usually less at the crown than at the skirt, in order to （）.Afacilitate the installation of piston ringsBallow for the expansion of the piston during operationCprevent crankcase vapors from entering the combustion chamberDreduce wearing of the upper cylinder liner
单选题Which of the listed cylinder liner surface conditions indicates proper lubrication?（）ADull black appearanceBBright appearanceCThin layer of lacquerDThick oily film
单选题The main function of piston compression rings is to （）Aprevent excessive cylinder liner wearBreduce friction losses in the engineCseal the space between the piston and the linerDlimit upward flow of lube oil into the combustion space
单选题The cylinder liner forming the cylinder wall and the inside of the water jacket is called a（）Adry linerBwet linerCjacket linerDcorrugated liner
单选题Low compression pressure in a diesel engine is caused by（）Alow water in the expansion tankBimproperly seated valvesClow fuel oil pressureDworn or broken cylinder liner sealing rings
单选题In order to increase the wearing resistance, the cylinder liner surfaces are sometimes （）.Aaluminum-platedBbronze-platedCzinc-platedDchromium-plated
单选题Low compression in a diesel engine could be caused by（）Aworn or broken cylinder liner sealing ringsBhigh cooling water temperatureCworn or broken piston ringsDlow fuel oil pressure
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The cylinder oil is pumped into the cylinder (via non-return valves) when the piston rings pass the lubricating orifices during （）Athe upward strokeBthe downward strokeCthe power strokeDthe suction stroke
单选题The cylinder oil will have to neutralize the acidic products of combustion and have good （） properties to keep the metal surfaces clean.AdetergentBde-oilingCdefrostingDdemulsifying
单选题All the rings are slightly rounded on their external top and bottom edges to keep the oil film on the cylinder liner during （） for new piston rings.Athe running-in periodBthe running processCgas exchange processDthe boiler firing
单选题The film of oil between the rings and the liner is not only essential for the lubrication but also （） achieving a gas seal.Aplay a great part onBrun a role inCplays an important part inDacts as important part at
单选题Engine coolant accumulating in the diesel engine lubricating oil can result from a （）Alow oil pressureBhigh coolant pressureCleaking fuel injectorDcracked cylinder head or liner
单选题There is a support ring between the cylinder block and collar of the cylinder liner, thus carrying both the liner and the cylinder coverIt also passes to the cooling bores and to the cover（）Acooling waterBcooling oilCrefrigerantDlubricate oil
单选题One of function of diesel engine lubricating oil is to （）Ainduce carbon formation on cylinder wallsBimprove fuel penetration in the combustion spaceCform a friction reducing film between mating surfacesDlubricate the fuel injection
单选题Piston compression rings used in a diesel engine function to （）Atransfer heat from the cylinder to the pistonBscrape oil from the sides of the pistonCseal the combustion space from the crankcasesDprevent any piston contact with the cylinder liner
单选题In order to keep the oil film on the cylinder liner during the running-in period, the piston rings are slightly rounded（）Aon both the external and internal top edgesBon both the external top and bottom edgesCon both the external and internal bottom edgesDon all the four edges
单选题If clearance between a piston and the cylinder wall is excessive, piston slap will occurThe slap itself is caused by （）Aalternation of side thrustBa breakdown of the lube oil film on the cylinder wallCworn piston boss piston pin bearingsDfluctuating gas pressure in the combustion space
单选题Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each cylinder during （）.Athe power strokeBthe compression strokeClow load operation onlyDperiods of standby