第四章關聯題108題

Passage1

Valvedrivemechanism

Thevalvedrivemechanismcommandstheinletandexhaustvalvesattherequiredtiming.

Thevalvedrivemechanismconsistsofaninletandexhaustcamfollower(8)eachsuspendedina

plungerofthetappetassembly(7),twotubularpushrods(4)withballjoints,twonodularcastironrocker

arms(2)suspendedinarockerarmbearingbracket,twoyokes(5)andayokeguidepins.SeeFig.4-1.

Thetappetrollersfollowthecamprofilesandtransferthemovementsthroughpushrodstotherocker

arms.Therockerarmsoperatetheinletandexhaustvalvesthroughyokes(5).Lubricationfortherocker

armscomesfromtheengine'ssecondaryoilsupplymanifoldthroughdrillingsinthecylinderheadand

rockerarmbracket.

Thetappetassemblyreceiveslubricatingoilviachannelsintheengineblockfromthemainsupply

manifold.Fortherollerandshaft,theoilissuppliedthroughtheguidingplunger.

Tocompensateforheatexpansionaclearancemustexistbetweentherockerarmandyoke.All

adjustmentshavetobedoneonacoldengineonly.

1.Accordingtothepassage,thebesttimetoadjustthevalveclearanceis.

A.beforetheengineisstartedB.whentheengineisrunning

C.aftertheenginehasjustbeenstoppedD.whensomethinghasgonewrongwiththeengine

2.Therollerandthetappetassemblyarelubricatedbymeansof.

A.themainlubesystemB.thesecondaryoilsystem

C.thespecialpumpingsystemD.theturbineoilsystem

3.Accordingtothepassage,thevalvedrivemechanismdoesnotinclude*

A.tappetrollersB.pushrodsC.nodularcastironD.yokesandguidepins

4.Toclosevalvestightly,whichclearanceshouldbeinspectedaccordingtothemaintenance

schedule?

A.Theonebetweenthecamandthetappetroller.

B.Tiieonebetweenthepushrodsandtheballjoints.

C.Theonebetweentherockeraimsandtheyoke

D.Theonebetweentwotubularpushrods.

5.Whichstatementaboutthepassageisnottrue?

A.AlladjustmentshavetobemadeonahotengineAonly.

B.Fortherollerandshaft,theoilissuppliedthroughtheguidingplunger.

C.Thevalvedrivemechanismcommandstheinletandexhaustvalvesattherequiredtiming.

D.Therockerarmsoperatetheinletandexhaustvalvesthroughyokes.

Passage2

Compressorcleaningduringengineoperation

Thecompressormaybecleanedbywaterinjectionduringtheengineoperation.Thecleaningprocess

willhavegoodresultsaslongasthedepositformationhasnotgonetoofar.Incaseaverythickhardened

crustofdirtthecompressorhastobedismantledforcleaning.

Inthismethodofcleaningthewaterisnotactingasasolventbutinsteadremovesthedeposits

mechanicallybytheimpactofthewaterdroplets.Itisthereforerecommendedtousecleanwaterwithout

additives.ThewatershouldnotcongKnanyadditiveswhichmightremainonthecompressorblades.

Periodicallycleaningofthecompressor(Fig.4-2)preventsordelaysexcessivebuild-upofdirtbutin

nowayreplacestheusualoverhaulswheretheturbochargeriscompletelydismantled.

Theturbochargerisprovidedwithawatercontainer(1).Duringthecleaningprocedurethecontainer

ispressurizedwiththechargeair(2)andfromwherethewaterisforcedtothecompressorinlet(3).

Fig.14-2Compressorcleaningdevices

1.Whichofthefollowingstatementscanbeusedtocleanthecompressorwiththeenginerunning?

A.WaterdropletsB.WaterwithadditivesC.ChargeairD.Hardcrust

2.Whatprincipalisusedinthismethodofcleaning?

A.Thecleansersolvesthedeposits.

B.Thecleansermeltsthedeposits.

C.Thecleanserbeatsthedepositsmechanically.

D.Thehighpressureofthecleanserremovesthedeposits.

3.Whichofthefollowingstatementsisnotcorrect?

A.Thecompressorneedsregularcleaning.

B.Periodicalcleaningofthecompressorcontributestoreducingbuild-upofdirt.

C.Itsnotnecessarytodismantletheturbochargerifperiodicalcleaningofthecompressoris

performed.

D.Additivesshouldbetterbeavoidedduringthecleaningprocess.

4.Thecleaningwatershouldnotcontainanyadditives,because.

A.theymaydelaybuild-upofdirtB.theymightremainonthebladesofthecompressor

C.theymaybeforcedtothecompressorinletD.theyarenotgoodsolvents

5.Thecleaningprocesswillhavegoodresultsif.

A.thereisaverythickcrustofdirtonthecompressorB.thecompressorisnotdismantled

C.thedepositformationisnotveryseriousD.thewaterdropletsaresmallenough

Passage3

Chargeaircooler

Theengineisequippedwithachargeaircooler.Theinserttypechargeaircoolerismountedina

weldedcasing(airtrunk).Tlietrunkisboltedtotheengineblock.

Standardisatwo-stagecoolermounted.Thefirststage,throughwhichthechargeairflows,iscooled

withwaterfromtheHTcoolingsystemandcoolsthechargeairtillapprox.90-\00蟆.Tiesecondstageis

suppliedwithwatercomingfromtheLTwatersystemandcoolsthechargeairmrthertilltherequired

temperatureofapprox.50X..BycontrollingthewaterflowthroughtheLTcoolerthechargeair

temperaturecanbekeptconstantattherequiredtemperature.

Thecirculatingcoolantwatershouldalwaysbeunderpositivepressureandshouldbeascleanas

possible.Theoperatingairtemperatureshouldbemaintainedbycontrollingthecoolantinlettemperature.

Whilsttheengineisrunningtheairandcoolanttemperaturesandpressuresatinletandoutletshould

becheckedandloggedperiodically.Variationsfromnormalindicatefaultsdevelopingsuchasfoulingof

thefilmplatesorobstructionofthewatertubes.

Checkdaily,duringoperationoftheengine,theworkingofthetelltaleholeatthefreeendofthe

chargeairreceiver.Thefunctionofthisholeistoinformtheoperatorthepresenceofwaterinthechargeair

receiver.Undernormalconditiononlycompressedairshouldescapefromthishole.

1.Accordingtothepassage,theexpression"HT"probablymeans.

A.HIGHTANKB.HIGHTEMPERATURE

C.HEATTRANSMISSIOND.HEATTRANSFER

2.Inordertomaintainthechargeairtemperatureweshouldcontrol.

A.thecoolantinlettemperaturecomingfromthefirststagecooler

B.thecoolantflowcomingfromthesecondstagecooler

C.thecoolantoutlettemperaturecomingfromthesecondstagecooler

D.thecoolantflowcomingfromthefirststagecooler

3.Thechargeairtemperaturedepartingfromnormalmayindicatethat

A.condensatecanbeformed

B.onlycompressedairshouldescapefromthetelltale

C.thefilmplatesarebecomingdirtyorthewatertubesareblockedbyscale

D.coolingwatermayhavebeencarriedintothecylinders

4.Thefunctionofthetelltaleholeisto.

A.detectwhethercompressedairhasescapedfromthehole

B.controlthecoolantinlettemperature

C.determinewhetherthecoolantwaterisunderpositivepressure

D.informtheoperatorthepresenceofwalerinthechargeairreceiver

5.Whichofthefollowingstatementsisnottrue?

A.Theengineisequippedwithachargeaircooler.

B.Atwo-stagecoolermountedisstandard.

C.ThefirststageiscooledwithwaterfromtheLHwatersystem.

D.Thesecondstagecoolsthechargeairfurthertillabout50℃.

Passage4

Thevibrationdamperservestoreducethetorsionalvibrationgeneratedbythecrankshaft.The

clamperconsistsofahousingandafreerotatinginertiaringsupportedbyanaxialbearing.Itfonnsa

totallyenclosedunit.Thefreespacebetweeninertiaringanddamperhousingisfilledwithahighviscous

fluid.Whenthecrankshaftrotatesatconstantspeed,theinertiaringwillfollowthismovement.The

combustionpressureexertedoneachpistongeneratesvibrationinthecrankshaft,andeachvariation

generatedbysuchavibrationwillaffectthemovementoftheinertiaring.Theresultingshiftoftheringto

thedamperhousingisopposedbytheviscousfluidandthevibrationwillbereduced.

Theenergy,absorbedduringtheprocess,isconvertedintoheatandthenradiatedtothesurroundingair.

Hence,properventilationofthedamperisessential.

Theviscousdamperfluidisduringengineoperationsubjectedtoageingandthefluidbecomesmore

viscous,hisendingfluidsamplesonaregularbasetothedampermanufacturertherateinreductionofthe

viscositycanbedetennined.Assamplingintervaltimeis6000hoursadvised.Damperswithatoohigh

fluidviscositymaycausecrankshaftbreakdown..

Thedampercoverhastwofillingholeslocated180*oppositeeachotherandclosedbyscrew-infiller

plugs.Ifoneoftheseplugsisaccessible,afluidsamplecontainercanbescrewedinandasampletaken

withthedamperinplace.Onasparedamper,samplingmustbeeffectedwiththedamperinthevertical

position.

Forliquidsampling,aspecialkitcanbeorderedfromStork-WartsilaDiesel.

1.Thegeneraldescriptionofthevibrationdampertellsusthat,

A.thefreespacebetweeninertiaringanddamperhousingisfilledwithalowviscousfluid

B.whentheinertiaringmovesatconstantspeed,thecrankshaftfollowsthismovement

C.thedamperismadeupofahousingandafreerotatinginertiaring

D.noventilationofthedamperisnecessaryasthevibrationreductionprocessabsorbslittleenergy

2.Whichofthefollowingstatementsisnottrueaboutmaintenanceoftheviscousdamper?

A.Samplingintervaltimefordeterminingthequalityofthefluidis6000hours.

B.Forliquidsampling,aspecialkitcanbeused.

C.Onasparedamper,samplingmustbeeffectedwiththedamperinplace.

D.Theviscousfluidinadamperbecomesmoreviscousastimegoesby.

3.Duringtheengineoperation,thevibrationdampercan.

A.transfertheenergyoftheengineB.absorbthecombustionheat

C.opposethecrankshaftrotatingD.reducethevibrationofthecrankshaft

4.Accordingtothepassage,welearnthattwofillingholesinthedampercoverareused

A.torechargethefluidB.toventilatethedamper

C.tofitthecontainerD.totakethesample

5.Ifthedamperfluidbecomeshighlyviscous,.

A.thetorsionalvibrationofthecrankshaftmaybereduced

B.thedampermayabsorbmoreheat

C.theinertiaringmayrotatefaster

D.thecrankshaftmaybreakdown

Thevibrationdamperemploysahighviscousfluidtoopposetheshiftoftheinertiaringtothedamper

housing.Itisnecessarytogetsamplestodeterminetherateinreductionoftheviscosity.Thestepstodraw

offthesampleareasfollows(RefertotheFig.4-3):

Fig.4-3Liquidsampling

1.Turntheengineuntilthedrainplugsareeasyaccessible.Donotunscrewthedrainpluguntilthe

damperislukewann(approx.401).

2.Carefullytapthelockingoftheupperdrainplugbackwards,usingapunch,andunscrewthe

threadedplug.Donotyetremovetheplug!

3.Unscrewonecapnutfromthe(plastic)liquidcontainer.

4.Removethedrainplugandscrewtheliquidcontainerinstead.

5.Removetheoutercapnutfromtheliquidcontainer.Makesurethatnomachineoilordirtcanenter

theliquidcontainer!

6.Screwtheoutercapnutagain,oncetheliquidhasreachedtheopenendoftheliquidcontainer.

Thefilling-upperiodoftheliquidcontainermaytakefromafewsecondsuptomorethananhour,

dependingontheliquidcondition.

7.Unscrewtheliquidcontainerfromthedamperandfitthedrainplugusinganewjointring(supplied

withthemountingkit).

8.Fitthesecondcapontheliquidcontainer.

Ifnosamplecanbetakeninthisway,youcanproceedasfollows:

-Ifstillnoliquidappearsafterawhile,removetheseconddrainplug,too.

-Supplynitrogenof3.5barmaximumpressurethroughtheopenfillinghole.

Ifnonitrogenisavailable,airmaybeused,providedthisairisproperlyfilteredanddry.

-Oncetheliquidhasreachedtheopenendoftheliquidcontainer,cutoffthesupplyofnitrogenand

screwthecapontheliquidcontainer.

-Afterthenitrogensupplyhascutoff,unscrewtheliquidcontainer,screwthesecondcapandfitboth

drainplugs.

Ifaliquidsamplecannotbeobtainedthiswayeither,itcanbeassumedthatthedamperliquidhas

thickenedtoaninadmissiblevalue,necessitatingthereplacementofthedamper.

1.Accordingtothepassage,wecanlearnthat.

A.beforeusingthecontainertodrawoffthesample,bothendsofitareclosed

B.theliquidcontainermustbewashedwithmachineoilbeforesampling

C.liquidsamplingmusttakemorethanonehour

D.twoliquidsamplesshouldbetakeneverytime

2.Iftheliquidsamplecannotbetakenanyway,itmeans.

A.nitrogenpressureistoolow

B.thequantityofthedamperfluidisinsufficient

C.theviscousfluidindamperbecomestoothick

D.themethodofliquidsamplingisincorrect

3.Whichstatementistrueaboutthesamplingprocess?

A.Thedrainplugcanbeunscrewedregardlessofthedampertemperature.

B.Thedrainplugshouldnotberemoveduntilonecapnutfromtheliquidcontainerisunscrewed.

C.Theoutercapnutmustbescrewedbeforetheliquidreachestheopenendoftheliquidcontainer.

D.Thedrainplugcanbefitbyusingtheoldjointring.

4.Ifnosamplecanbetakenbyremovingthefirstdrainplug,thenwhichofthefollowingisdone?

A.tlieseconddrainplugshouldberemovedtoo.

B.Apressureof5.3barshouldbeapplied.

C.Cleananddampairisusedinsteadofnitrogenifthelatterisnotavailable.

D.Tlienitrogensupplycontinueswhentheliquidhasreachedtheouterendoftheliquidcontaine匚

5.Duringthesamplingprocess,ifnonitrogenisavailable,maybeused.

A.freshairB.dryandproperlyfilteredairC.wetairD.hotair

Passage6

Atthefirststart,listencarefullyforpossiblejarringsounds.Ifanythingissuspected,stoptheengine

immediately,otherwisestoptheengineafter5minutes1idling.Checkatleastthetemperaturesofthemain

andbigendbearingsandofallotherbearingswhichhavebeenopened.Makevisualinspectionfrombelow

tothecylinderlinersandpistonskirtswhichhavebeenopened.Ifeverythingisinorder,restart.

Checkthatthereisnoleakageofgas,water,fuelorlubricatingoil.Especiallyobservethefuellines,

HPfuelpumpsandinjectors.Watchthequantitiesemergingfromtheleakoilpipes!

Checkthatthestartingairmanifoldisnothotatanycylinder(leakystartingvalvemaycause

explosion!

Afteroverhaul,thefollowinginstructionsareimportant;

-checkpressureandtemperaturegauges.

-checktheautomaticalarmandstopdevices.

-checkthepressuredropoverthefuelfilterandlubricatingoilfilter.

-checktheoillevelintheoilsump/oiltank.Estimatetheconditionoftheoil.

-checkthede-aeratingoftheenginecirculatingwatersystem.

-checkthequantityoffuelleak.

-checkthetelltaleholesforleaks.

-checkthecirculatingwaterquality

-checkthecylinderpressures.

-listenforjarringsounds.

-checkthecrankcasepressure.

-checkthestartingairmanifold.

Running-inismainlyintendedtoletpistonrings"wear'1tofitproperlyinthecylinderliner.

Donotcontinuouslyrunatconstantloadduringtherunning-inprocess(Fig,4-4).

Itisimportanttovarytheloadseveraltimes.Theringgroovesinthepistonwillhaveadifferenttilting

A=--------------Operatinghours

B=----------------

Fig.4-4Running-inprocedure

1.Paragraph1tellsusthat

A.ifwehearvibrationsounds,weshouldstoptheenginequickly,orallowittooperateatlow

speedfor5minutes,thenstopitandcheckeverything

B.ifwehearvibrationsounds,weshouldstoptheenginequickly,otherwisetheenginewillbe

stoppedautomaticallyafter5minutes

C.ifwehearexplosionsoundsweshouldstoptheenginethencheckeverything

D.ifwehearsurgingsounds,weshouldstoptheengineimmediatelyotherwiseafter5minutesthe

enginewillbedestroyed

2.Afteroverhaul,followinginstructionsareimportantexcept.

A.releaseairfromtheenginecirculatingwatersystem

B.treatthecirculatingwaterifnecessary

C.makesurethepressuredropisenoughbesidesthefuelfilter

D.makesurethequantityoflubeoilmeetstherequirement

3.Afterpistonoverhaul,therunning-inprocessshouldbecarriedout.

A.periodicallyatsteadyloadB.occasionallyatvariousload

C.continuallyatconstantloadD.continuallyatvariousload

4.Whendealingwithenginetroubles,.

A.noleakageoflubricatingoilshouldbechecked

B.quantitiesofoilemergingfromtheleakoilpipesmustbewatched

C.qualityoftheleakoilmustbewatched

D.thenumberoftheleakingfuellinesshouldbechecked

5.Whenshouldtheengineberestartedafterinspection?

A.Aftermakingvisualinspectionfrombelow.

B.Afterstoppingallbearingsthathavebeenopened.

C.Whenpistonskirtshavebeenopened.

D.Wheneverythingisinorder.

Passage7

Thissequenceofeventsismadepossiblebysubstitutingportsinthebottomofthecylinderwallfor

theinletandexhaustvalves.Therearetwogroupsoftheseports,oneforexhaustandtheotherfor

scavengingair,usuallyontheoppositesidesofthecylinder,butinsomedesignsbothgroupsarcarranged

onthesameside.Theexhaustportsconnectwiththeexhaustmanifold,whilethescavengingports

communicatewiththescavengingairreceiverinwhichlow-pressureairisstored.Theexhaustportsare

slightlyhigherthanthescavengingports,sothattheyareuncoveredbythepistonwhilethescavenging

portsarestillclosed.

(Thefollowing2questionsarebasedonthepassageabove.)

1.Fromtheparagraphabove,weknowthat.

A.Ingeneral,bothexhaustportsandscavengingairportsareontheoppositesidesofthecylinder

B.Theexhaustportsareontheoppositesides,butthescavengingairportsareonthesamesides

C.Thescavengingairportsareontheoppositesides,buttheexhaustportsareonthesamesides

D.Twogroupsofpartsareneverarrangedonthesamesides

2.Accordingtotheaboveparagraphtheexhaustportslinkwith.

A.theexhaustvalvesB.thescavengingairreceivers

C.theexhaustmanifoldD.thescavengingports

Theengineisalsoprovidedwithagovernorwhichisdesignedtoregulatetheengine'sspeedby

adjustingthequantityofoilinjected.Whentheenginerunsataspeedhigherorlowerthanthatisset,the

governorwillactautomaticallyreduceorincreasethefueloilsupplysothattheenginecanbeadjusted.

(Thefollowing3questionsarebasedonthepassageabove.)

3.Fromthisparagraphwecanunderstandthat.

A.iftheenginerunsataspeedhigherthanthatisset,thegovernorwillincreasethefueloilsupply

B.iftheenginerunsataspeedhigherthanthatisset,thegovernorwilldecreasethefueloilsupply

C.thegovernorwillnotactuntiltheenginerunsatspeedlowerthanthatisset

D.thegovernorregulatestheengine,sspeedbyadjustingthefueloilinjection

4.Theenginegovernorisusedfor.

A.adjustingthefueloilinjectionqualityB.adjustingtheenginespeed

C.keepingtheengineathigherspeedD.keepingtheengineatlowerspeed

5.Accordingtotheparagraphwhatdoes"which"referto?

A.EngineB.GovernorC.SpeedD.Thequantityofoilinjected

Passage8

Thelubricationsystemofanengineprovidesasupplyoflubricatingoiltothevariousmovingpartsin

anengine.Itsmainfunctionistoenabletheformationofafilmofoilbetweenthemovingparts,which

reducesfrictionandwear.Thelubricatingoilisalsousedasacleanerandinsomeenginesasacoolant.

Theusualmethodofbearinglubricationisbyforcedfeedsystem,whichsuppliesoiltoallbearings,so

thatafilmofoilismaintainedonthejournalandbearingsurfaces.

(Thefollowing3questionsarebasedonthepassageabove.)

1.Theforcedfeedsystemisputintouseinorderto.

A.supplyoiltoallpartsoftheengine

B.lubricatethebearingandthepiston

C.maintainafilmofoilonthejournalandbearingsurfaces

D.maintainafilmofoilonthepistonsurfacesonly

2.Accordingtotheparagraph,whatdoes"its"referto?

A.thelubricationsystem'sB.lubricatingoils

C.thevariousmovingparts'D.thepistonsurfaces*

3.Whatisthefunctionoflubricatingoil?

A.Formationofafilmofoilbetweenthemovingparts,whichreducesfrictionandwear.

B.Usedasacleaner.

C.Asacoolantinengines.

D.Alloftheabove.

Freshwaterisusedforthecoolingofthecylinderjacketsandcoversofthemainengine,whereasthe

variouscoolingliquidswhichcirculatetheenginearethemselvescooledbyseawater,suchas,seawateris

usedforthecoolingoftheoilinthelubricatingoilcooleraswellasthefreshwater.Inanemergency

situation,forexampleintheeventofdamagetoafreshwatercoolerorgenerator,theseawaterpumpscan

beusedtosupplyseawatertothefreshwatercoolingsystem,merelybyremovingtheblind-flanges.

(Thefollowing2questionsarebasedonthepassageabove.)

4.Inwhichsituationweshoulduseseawatersysteminsteadoffreshwatersystem?

A.Whenseawaterpumpsaredamaged.B.Whenseawatercoolerisdamaged.

C.Whenfreshwaterpumpsaredamaged.D.Theblind-flangesarebroken.

5.Theword“merely"inthisparagraphcouldbestbereplacedby.

A.onlyB.necessaryC.butD.if

Passage9

Becausetheexhaustgasdriventurbo-blowercannotprovideenoughairatlowenginespeeds,the

pressurizedairshouldbecooledtoincreasethechargeairdensity.Astheairpassesthroughthechargeair

cooler,itstemperaturemaybereducedandmoisturecondensed,withthecondensateindangerofbeing

carriedintotheengine.Soawaterseparatorshouldbemountedbeneaththebottompartoftheengine

inletmanifold.

(Thefollowing2questionsarebasedonthepassageabove-)

1.Awaterseparatorisusedinorderto.

A.keepdieairfrombeingcarriedintotheengineB.keepthemoisturefrombeingcondensed

C.keepthedangerfrombeingcarriedintotheengineD.takeawaythecondensatefromtheair

2.Whyshouldweuseachaigeaircooler?

A.Inordertoincreasethechargeairtemperature.B.Inordertoincreasethechargeairpressure.

C.Inordertoreducemoisturecondensed.D.Inordertoincreasethechargeairdensity.

Lubricatingoilfromthecompressorwillpassalongtheairlinesanddepositonthem,intheeventofa

cylinderairstartingvalveleaking,hotgaseswouldpassintotheairpipesandignitethelubricatingoil.

Ifstartingairweresuppliedtotheengine,thiswouldfurtherfeedthefireandcouldleadtoan

explosioninthepipelines.Inordertopreventsuchanoccurrence,cylinder-startingvalvesshouldbe

properlymaintainedandthepipelinesregularlydrained.Alsooildischargedfromcompressorsshouldbe

kepttoaminimum,bycarefulmaintenance.

(Thefollowing3questionsarebasedonthepassageabove.)

3.Whichofthefollowingmaycauseanexplosionaccordingtothepassage?

A.Startingaircannotbesuppliedintotheengine.

B.Airstartingvalveleaksandstartingairissuppliedintotheengine.

C.Cylinder-startingvalvesareproperlymaintained.

D.Oildischargedfromcompressorsiskepttoaminimum.

4.Inordertoavoidignitingthelubricatingoilandleadingtoanexplosioninthepipelines,

A.pipelinesshouldberegularlydrained

B,cylinder-startingvalvesshouldbeproperlymaintained

C.oildischargedfromcompressorsshouldbekepttoaminimum

O.A+B+C

5.Fromtheparagraphmentionedabovewecanknowthat

A.thelubeoilispassinganddepositingontheoiltransferringline

B.thehotgaseswillcertainlycausethelubeoiltobum

C.thecompressormakesthelubeoilpassthroughthestartingvalve

D.oncetheleakingofstartingvalveoccurs,hotgasesmaycausethelubeoiltobumintheairpipes

Passage10

Fueloilisthoughttobeoneofthemainfactors,havingmuchtodowiththeoperationand

maintenanceofanengine.Thefueloilsystemforadieselenginecanbeconsideredintwoparts:thefuel

supplyandthefuelinjectionsystem.Whentheatomizedfuelisinjectedintothecombustionspace,ignition

isnotaltogetherinstantaneous,adefinitetimelagbeingmeasurablebetweenthetimeofinjectionand

ignition.Theperiodofignitionlagdepends,amongotherfactora,ontheig