单选题The carbon deposits on the piston crown and in the ring grooves （）.Ashould be scrapedBshould be derustedCshould be drilled outDto be brushed off
单选题
The carbon deposits on the piston crown and in the ring grooves （）.
A
should be scraped
B
should be derusted
C
should be drilled out
D
to be brushed off
参考解析
解析：
暂无解析
相关考题：
In a diesel engine, when refitting piston rings you should ①check the ring gap at the smallest diameter of the cylinder ②remove carbon from the ring grooveA.①B.②C.①②D.neither ① nor ②
In a diesel engine, when refitting piston rings you should______. I. check the ring gap at the smallest diameter of the cylinder II. remove carbon from the ring grooveA.I onlyB.II onlyC.both I and IID.neither I nor II
单选题The lowest ring of a piston is （）.Aa coil springBa sealing ringCan oil distributor ringDmain seal ring
单选题“The use of a poor quality oil can lead to rapid deterioration of its properties with the resultant formation of deposits in the piston crown which in turn results in a considerable reduction in heat transfer with subsequent overheating and thermal cracking” According to this sentence, we can know that the principle reason of the overheating and thermal cracking is（）Athe use of a poor quality oilBthe deterioration of its propertiesCthe formation of depositsDthe reduction in heat transfer ability
单选题In some diesel engine designs,（）the injection of cylinder oil is timed to impinge when the piston and only impinge on（）Ais coming upward；cylinder ring beltBis going downward；piston ring beltCis coming upward；piston ring beltDis going downward；cylinder ring belt
单选题A diesel engine piston ring face is in direct contact with the （）.Atop of the ring grooveBcylinder liner oil filmCbottom of the ring grooveDback of the ring groove
单选题The cooling of the piston is carried out by circulating （） across the underside of the crown and inside the ring belt or through specially shaped passages.Asea waterBscavenging airClubricating oilDfuel oil
单选题In a diesel engine, when refitting piston rings you should （） Ⅰ.check the ring gap at the smallest diameter of the cylinder Ⅱ. Remove carbon from the ring grooveAⅠ onlyBⅡ onlyCboth Ⅰ and ⅡDneither Ⅰ nor Ⅱ
单选题A condition contributing to diesel engine piston rings sticking in the ring grooves, is insufficient ring clearance at the ring（） Ⅰ.gap Ⅱ.sideAⅠonlyBⅡ onlyCboth Ⅰ and ⅡDneither Ⅰ nor Ⅱ
单选题Cracking of a diesel piston crown can result from（）AExcessive piston to liner clearanceBThe underside of the piston crown being excessively dirty lowering the rate of heat transferCFaulty nozzle sprayDAll of the above
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The piston crown employs the usual jet-shaker principle with an arrangement of cooling bores in the crown so that the surface temperatures of the crown are moderate with a very even distribution（）Awater coolingBoil coolingCair coolingDcombined cooling
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Which of the following characteristic of lube oil helps to reduce the amount of deposits in the piston ring belt during the combustion process in a diesel engine?（）ALow viscosity indexBLow carbon forming tendenciesCHigh film strengthDHigh non-corrosive qualities
单选题Diesel engine piston ring blow-by is usually caused by excessive ring clearance at the ring（）AbackBsideCgapDbottom
单选题The clearance volume for a single stage compressor is defined as the space created between the （）.Atop of the piston and bottom side of head, with the piston at BDCBpiston and head, including the space around the piston to the top of the upper ring and under the valves, with the piston at TDCCbottom of the piston and bottom side of the head at TDC, regardless of upper ring location and valve placementDtop of the piston and bottom side of the head at TDC as compared to that which exists between the top of the piston and bottom side of head at BDC
单选题In the sentence “In some designs the cylinder oil is timed so that the oil injects only on the piston ring belt, the "piston ring belt" means （）.Apiston crownBpiston ring grooveCpiston skirtDpiston ring area
单选题A condition contributing to diesel engine piston rings sticking in the ring grooves, is insufficient ring clearance at the ring（）AgapBsideCbackDradial
单选题In a large, low-speed diesel engine the clearance between the piston crown and cylinder head is found to be excessiveIn order to correct for this, you should（）Abuild up the piston crown by metal sprayingBbuild up the cylinder head by metal sprayingCinsert shims between the crankpin bearing box and the connecting rod footDinstall a thinner head gasket
单选题Persistent knocking in one cylinder of a diesel engine could be caused by（）.Aa low load on that cylinderBsluggish piston ring actionCexcessive piston crown coolingDexcessive clearance of piston pin
单选题Why is the ring belt narrower in diameter than the skirt of a piston designed for a diesel engine?（）ATo allow for greater expansion due to higher operating temperatureBTo seal the cylinder against leakage of combustion gasesCTo provide an additional surface for oil coolingDTo provide an additional strength for the crown and lower structure
单选题If the compression rings on a diesel engine piston become stuck in the ring groove, the cause may be due to（）Aexcessive ring actionBexcessive ring temperatureCimproper ring rotationDexcessive ring face wear
单选题The sealing function of the piston ring is brought about by the gas pressure above and behind the piston ring, which forces it （） against the bottom of the ring groove, and （） against the cylinder wall.Aupwards；inwardsBupwards；outwardsCdownwards；inwardsDdownwards；outwards
单选题A diesel engine piston crown can crack from （）Aexcessive piston to liner clearanceBexcessive dirt beneath the piston crown that reduces heat transferCfaulty nozzle sprayDall of the above
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Which of the following conditions would cause carbon deposits to form in the piston ring belt of a diesel engine?（）Afaulty combustionBexcessive ring temperatureCover lubricationDall of the above