单选题Black areas on the sealing surfaces of piston rings indicate（）Alube oil pumpingBrotating ringsCgas pressure behind the ringDpassage of hot gases
单选题
Black areas on the sealing surfaces of piston rings indicate（）
A
lube oil pumping
B
rotating rings
C
gas pressure behind the ring
D
passage of hot gases
参考解析
解析：
暂无解析
相关考题：
The sealing rings are in four parts and pressed together around the piston rods by means of _____A.nutsB.boltsC.coil springsD.stuffing boxes
Among the rings of a piston the ______one is subjected to the greatest load and temperature.A.bottomB.middleC.topD.any position
Before replacing a piston you should check that all rings are ___.A.freeB.fastenedC.brokenD.stuck
单选题Around the combustion chamber, all the main components are to give low thermal strains and the smallest, circumferentially symmetric deformations for good sealing between piston rings and liner（）Adrill cooledBhole cooledCtube cooledDbore cooled
单选题The lowest ring of a piston is （）.Aa coil springBa sealing ringCan oil distributor ringDmain seal ring
单选题If the piston groove drain holes for the oil control rings become clogged, which of the following is likely to occur?（）AThe oil control rings will seal improperly and wear rapidlyBThe piston will overheat due to insufficient lubricationCExcessive oil will remain on the cylinder wallDLight brown smoke will emanate from the engine exhaust
单选题Insufficient end clearance on newly fitted piston rings in a diesel enginewill cause the rings to（）Ajam in the most worn part of the cylinder when the rings expandBbreak in the most worn part of the cylinder when the rings expandCwear eccentrically on the side opposite the end gapDoverheat and jam at the top center on the combustion stroke
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Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）Astarting the engine while hotBknurling the piston skirtCoperating the engine overheatedDscuff resistant piston rings
单选题When good and steady service conditions have been achieved, the running surfaces of the piston rings and cylinder liner will be（）In addition, the rings will move freely in the grooves and also be well oiled intact, and not unduly worn.Ahazy lightBhazy light brownChazy light blueDhazy light grey
单选题Visual inspection of chrome-plated piston compression rings reveals a black ring face at the position of the cylinder liner portsThis condition indicates a ring which（）Ahas a crown-faceBexceeds wear limits through normal wearChas excessive blow-byDis in good condition
单选题Scuffed cylinder liner wearing surfaces in a diesel engines can result from （）Achromium plating piston ringsBknurling the piston skirtCextended maximum power operationDapplying load to a cold diesel engine
单选题In a medium speed diesel engine, a trunk type piston may be cooled by（） Ⅰ.oil circulation though passages in the piston crown Ⅱ.heat transfer through piston rings and liner wallAⅠ onlyBⅡ onlyCeither Ⅰ or ⅡDneither Ⅰ or Ⅱ
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Before replacing a piston you should check that all rings are （）.AfreeBfastenedCbrokenDstuck
单选题If over a period of time, the oi1 film partially disappears, so that dry areas are formed on the cylinder wall, these areas and the piston surfaces will by frictional interaction, become finely scuffed and hardened, iegood mirror surface" will have deterioratedWhat condition of the piston rings can result in this phenomenon?（）Amicro-seizureBstickingCscratchedDbreakage/collapse
单选题Scuffed cylinder liner surfaces in a diesel engine can result form（）Astarting the engine hotBknurling the piston skirtCoperating an overheated engineDusing scuff resistant piston rings
单选题The function of the piston compression rings used in a diesel engine is to （）Aseal the space between the piston and linerBtransmit heat from the piston to the cylinder linerCreduce the amount of combustion gas blow-byDall of the above
单选题The main purpose of the piston oil scraper rings is to （）.Aseal the space between the piston and the linerBreduce the amount of lube oil burned in the combustion chamberCtransmit heat from the piston to the cylinder linerDdamp out fluctuations of the piston side thrust
单选题The sealing rings are in four parts and pressed together around the piston rods by means of （）.AnutsBboltsCcoil springsDstuffing boxes
单选题Each piston stuffing box is provided with two sealing rings and three（）ApackingsBpiston ringsCdistributor ringsDscraper rings
单选题A bright shiny appearance of the sealing surfaces on diesel engine compression rings indicates（）Acombustion gas blow-byBexcessive lubricationCproperly functioning ringsDinsufficient cylinder cooling
单选题If the piston ring gap remains insufficient when installing new rings, youshould（）Ainstall oversized ringsBhone the cylinder liner to allow ring installationCcompress the rings tighter with a compressing toolDfile the ends of the rings
单选题Which term describes piston pins having bearing surfaces in both the piston bosses and connecting rod eye?（）AStationaryBFull floatingCSemi-floatingDFree rolling
单选题The function of diesel engine piston compression rings is to （）.Aprevent piston side thrustBprevent engine friction lossesCtransmit heat from the piston to the cylinder linerDremove oil from the cylinder combustion space
单选题If due to thick and hard deposits of carbon, the piston rings cannot move freely in their grooves, dark areas will often appear on the upper part of the cylinder wall (may not be the risible at port inspection)What condition of the piston rings can result in this phenomenon?（）Amicro-seizureBstickingCscratchedDbreakage/ollapse
单选题Around the combustion chamber, all the main components are bore cooled to give low strains and the smallest, circumferentially symmetric deformations for good sealing between piston rings and liner（）AthermalBmechanicalCplasticDelastic