MB Engine History

8/3/2019 MB Engine History

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ThehistoryofthegasolineengineatMercedes-

Benz

THEHISTORYOFTHEGASOLINEENGINEATMERCEDES-BENZ...............................2

THEDEVELOPMENTOFTHEGASOLINEENGINE.......................................................4

CARLBENZANDTHEHIGH-SPEEDFOUR-STROKEENGINE...................................13

GOTTLIEBDAIMLER,WILHELMMAYBACHANDTHEGRANDFATHERCLOCK..24

THEMERCEDES-BENZGASOLINEENGINEFROM1926ON..................................46

MERCEDES-BENZGASOLINEENGINESAFTERTHESECONDWORLDWAR...........53

THECARBURETORERACOMESTOANEND...........................................................79

MERCEDES-BENZGASOLINEENGINESINRESEARCHANDMOTORSPORTS.........108

TIMELINE:THEHISTORYOFTHEGASOLINEENGINEATMERCEDES-BENZANDITS

PREDECESSORCOMPANIES..................................................................................120

PressInformation

Date:

June2008

Contact:

JosefErnst Telephone:+49(0)711-17-764


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ThehistoryofthegasolineengineatMercedes-

Benz

Unparalleleddevelopmentofthegasolineenginesincetheinventionoftheautomobilein1886

TechnologicalpotentialfarfromexhaustedThefour-strokegasolineenginewastheheartofthefirstmodern

automobiledesignedbyGottliebDaimlerandCarlBenzin1886.

Independentlyofoneanother,thetwopioneersdevelopedsmall,

high-speedengines,basedonNikolausOttosfour-stroke

principle,forthedrivesystemofnewautomobiles.Sincetheuseof

theseenginesintheBenzpatentmotorcarandDaimlersmotorcarriage,thefour-strokegasolineenginehasexperienced

unparalleleddevelopment.

Withtheirconstantinnovation,DaimlerAGanditspredecessor

companieshaveplayedanimportantroleinthesuccessstoryof

thisinternalcombustionengineformorethan120years.Itwas

thankstotheirtirelessworkthatthesingle-cylinderpowerunitof

theautomobilepioneersbecameanultra-moderndrivesystem,especiallyforpassengercars.

TheevolutionofthegasolineengineinMercedes-Benzvehiclesis

thereforethestoryofthecontinuousimprovementofnumerous

details.Evenwithinindividualengineseries,continuousrevision

wastestamenttothepursuitoftheperfectengine.Timeandagain,

theengineersincreasedoutputandtorqueontheonehand,and

reducedconsumptionandemissionsontheother.Thisprocessincorporatedbothdirectresultsfromcorporateresearchandthe

experienceMercedes-Benzgainedfromtheuseofgasoline


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Thishistoryisforeverbeingrewritten,becausetheMercedes-

Benzenginespecialistsarenotcontenttositontheirlaurelsand

declarethemselvessatisfiedwithoneofthehighstandardsthat

theysetforthemselvestimeandagain.Thecurrentgenerationof

gasolineenginescanalwaysbeimprovedfurther,ashasbeen

shownby125yearsofexperience.Thatishowlongithasbeen

sinceGottliebDaimlerandWilhelmMaybachresignedfromthe

Deutzenginefactoryinordertodeveloptheirhigh-speedfour-

strokegasolineengine,calledtheGrandfatherClockbecauseofits

appearance.By1883,theenginehadalreadyworkedforthefirst

time,and,twoyearslater,CarlBenzsfour-strokeenginewasalso

readyforuse.Sincetheseenginespubliclypoweredtheworlds

firstautomobilesin1886,theevolutionofgasolineengine

technologyhasprogressedwithuninterrupteddynamism.The

latestexampleisthenewDIESOTTOenginepresentedinthe

Mercedes-BenzF700researchvehicleattheFrankfurt

InternationalMotorShow(IAA),whichcombinestheadvantages

ofthegasolineenginewiththoseofthedieselengine.


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Thedevelopmentofthegasolineengine

AdrivesystemusingcontrolledexplosionsGasolineasafuelusedatalaterstagePatentforthefour-strokegasolineenginein1877ThemostimportantpowersourceduringtheIndustrial

Revolutionwasthesteamengine.However,thesemachineswere

solargeandheavythattheywerehardlysuitableforpowering

automobiles.Thiswasdueinparticulartothespatiallyseparated

generationandmechanicaluseofsteam.Incategoriesbelowthe

railwaylocomotiveandthetractionengine,whichwasprincipally

usedinagriculture,novehiclecouldbeefficientlyoperatedbya

steamengine.Ofcourse,thereweredifferentmodelsofsteam-

poweredautomobilesandtrucks.However,thepursuitofan

alternativeengineforroadvehiclesaswellasforsmall-scale

tradesandindustrywastobecomeaseparatechapterinthe

historyofthesteamengine.

Agoodsolutionfortheengineneedsofsmallcompaniesandcrafts

businessesappearedtobethedirect-action,coal-gas-operatedinternalcombustionengine.Theinfrastructureforprovidingsuch

engineswascreatedinthefirstthirdofthenineteenthcentury:in

1807,theworldsfirstevergasstreetlightwasinstalledinLondon

bywayoftrial.Afewyearslater,thedevelopmentofapubliccoal

gasnetworkbeganintheBritishcapital,andothercitiesand

industrialtownsaroundtheworldfollowedsuitsoonafterwards.

Gaspistolsandpowderengines

Thedreamoftheinternalcombustionenginewasconsiderably

olderthanthe asnetwork however.TheDutchscientist


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ChristiaanHuygens(16291695)hadalreadydevelopedan

atmosphericenginethatoperatedwithgunpowder.In1673,

Huygensdemonstratedhispowderengineinpublic.Itachievedits

taskinthattheexplosionofthepowderproducedapartial

vacuuminthecylinder,andthepistonthatwasshotupwardsby

theexplosionwasthenpusheddownagainbytheatmosphere.

However,Huygenswasunabletoproducecontinuousrunningof

theenginefromthissingleignition.

Theprincipleoftheignitionofgasusinganelectricsparkhadalso

beenknownforalongtime.Amongstthepredecessorsofthe

moderngasolineenginewasthegaspistol,demonstratedin1776

bytheItalianscientistAlessandroVolta(17451827).Inorderto

demonstratetheworkingofelectricity,heignitedamixtureof

methaneandairinaglasscylinderwiththeaidofanelectric

spark.Thesubsequentexplosionforcedthestopperoutofthe

cylinder.

Lenoirsgasengine

Theworldsfirsttrulyviableinternalcombustionenginewasthe

atmospherictwo-strokegasenginebyJeanJosephEtienneLenoir

(18221900).TheLuxembourg-borninventordevelopedhis

double-actingtwo-strokeenginein1859.IntheLenoirengine,the

non-compressedmixtureofcoalgasandairwasalternatelyand

electricallyignitedonbothsidesofadiskpiston.Fortheignition,

LenoirusedthesparkcoildevelopedbyDanielRuhmkorff.

However,thepowerwasproducednotbytheexplosionofthe

mixture,butbytheatmosphericpressurethatcounteractedthepartialvacuumcreatedbycombustion.

InJanuary1860,Lenoirshowedhisengineinpublicforthefirst


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time,anditwasmetwithgreatenthusiasm.Inthefollowingyears,

severalhundredenginesofthistypewerebuilt,withanoutputof

between0.25hp(0.19kW)and4hp(2.9kW).Owingtothehigh

operatingcostscomparedwithasteamenginewiththesame

output,theLenoirgasenginewasfavoredprimarilyinthoseareas

wherecontinuousoperationwasnotrequiredi.e.wherethegas

enginewasabletomakeuseofitsadvantageofalwaysbeing

quicklyreadyforuse.

Fatherofthefour-strokegasolineengine:NikolausAugust

Otto

TheLenoirenginealsoinspiredthebusinessmanNikolausAugust

Otto(18321891)andhisbrotherWilhelmtoexperimentwith

enginedesign.ShortlyafterthepresentationoftheFrenchgas

engine,theyoungmen,whowereoriginallyfromtheTaunusarea

ofGermany,begantheirownexperimentstotrytobuildapower

machinesuperiortotheLenoirsystem.Afirstpatentforthe

provisionoffuelbyturningethylalcoholtogaswasdeniedthe

twoinventorsinPrussiain1861.Fromamodernperspective,this

rejectionseemsparticularlyincomprehensible,since,withthis

concept,theOttobrotherswerealreadyenvisagingtheuseoftheir

enginetopowervehicles.

Owingtoincreasingdifficulties,WilhelmOttosoonwithdrewfrom

theenginedevelopmentbusiness.Nikolaus,however,continued

theexperimentsandhadhisfirstmodelenginebuiltin1861.It

becamethestartingpointforthefour-strokegasengine,the

inventorreflectedinretrospect.In1862,Ottofinallyhadafour-cylindertrialenginebuiltbyMichaelJosephZonsatthe

mechanicalworkshopofJ.ZonsinCologne.Throughthe

introductionofanewcompressionstrokeduringearlier


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experiments,Ottohadworkedoutthefunctioningofthefour-

strokeprocess,whichhenowimplementedinthismodel.Every

operatingcycleoftheengineconsistedofthefollowingsteps:

mixtureintake,compression,ignition,anddischargeofthe

exhaustgas.Thisfour-strokeengineappearsparticularly

visionarytoday,since,eventhen,manyofitsdesign-engineering

detailsweresimilartothoseoflaterengines.

However,thedesignofthepistonswasunusual:eachcylinderwas

equippedwithanauxiliarypiston.Thiswasintendedtominimize

thestrengthoftheignitioninthattheexplosionactedinitiallyon

theoperatingpistonwhichwaspressedintotheauxiliarypiston

andcompressedtheaircontainedtherein.Theforcethus

transmittedwaspassedonbytheauxiliarypistontothe

crankshaft.Themechanicalactionwasthereforedelayedand

cushionedbytheair.Inthisway,Ottosoughttoobtain

particularlysmoothrunning.Insteadhowever,theunpredictable

actionoftheauxiliarypistonproducedveryirregularrunning,and

ultimatelydestroyedthetrialengine.

Moveawayfromthedirect-actingfour-cylinderengine

Asaresultoftheseproblems,Ottodecidedtobuildan

atmosphericengine.Inanatmosphericinternalcombustion

engine,theexplosiondidnotdamagethemechanicsbecausethe

pressureoftheexplosionmovedthepistonupwards.However,a

mechanicallinkagetothepowertrainwasproducedonlyattop

deadcenter.Afterthecoolingofthecombustiongasesinthe

cylinder,theatmosphericpressureandtheweightofthepistongeneratedthepower.

Thestructureagaincontainedanauxiliarypiston.Whenthegas-


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airmixturewasignited,theexplosioninitiallyshottheoperating

pistonupwards,thelatterconnectedviaahollowpistonrodtothe

auxiliarypiston.Bothpistonswerenowmechanicallycoupled.The

atmosphericpressurethusactedonbothpistonsandgenerated

powerinthatitforcedtheoperatingandauxiliarypistonstothe

floor.Atbottomdeadcenter,thepistonswerereleasedfromone

another,andtheauxiliarypistonroseupagainbecauseofthe

inertiaoftheflywheel.There,theoperatingpistoncontactedit

afterthenextexplosion.Withhiscomplexarrangement,Nikolaus

Ottoobtainedtheintendedseparationofthedriveshaftfromthe

impactoftheexplosions.

MechanicalengineeringcompanyN.A.Otto&Cie.

WhenOttohadthisenginepatented,hehadhardlyanyfundsleft.

Inthistimeoffinancialneed,helpwasprovidedthroughcontact

withtheCologne-basedengineerEugenLangenwhomhemetin

1864.Thetwomenfoundedthemechanicalengineeringcompany

N.A.Otto&Cie.,inwhichLangenwasalimitedpartner.Eugen

Langenalsocontributedtothesuccessofthebusinessasan

engineer.Hedevelopedthefreewheelclutch,whichwasnecessary

forasmoothchangebetweenthepowertransmission,duringthe

actionoftheatmosphericpressure,fromthetoothedrackofthe

auxiliarypistonstothedriveshaft,andthefreewheelingafterthe

ignitionofthemixture.In1866,forthethusamendedengine,Otto

wasfinallygrantedthecovetedPrussianpatenthisoriginal

designhadbeenpatentedonlyelsewhereinEurope.

AttheWorldExhibitioninParisin1867,OttosenginewasfavoredoverLenoirsengineandothergasengines.After

measuringthegasconsumption,thejuryevenawardedtheGrand

PrixtotheGermanenginebecauseOttosenginerequiredless


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thanhalfthegasofotherengines.Thisinternationalapprovalwas

thebasisforproductiononalargerscale,andbroughtthe

companyeconomicstability.Aswellastheincorporationofthe

company,in1872thenamewaschangedtoGasmotoren-Fabrik

DeutzAG(DeutzGasEngineFactory).In1872,GottliebDaimler

wasappointedmemberofthedirectorateofGasmotoren-Fabrik

DeutzAG,acompanywhichhademergedfromN.A.Otto&Cie.

DaimleralsobroughtthedesignengineerWilhelmMaybachwith

himtoOtto.In1875,Maybachwasalreadyattemptingtoconvert

theatmosphericenginetogasolineoperation.Hisfirstsuccesswas

obtainedwithawadofragssoakedingasoline,whichheheldin

frontoftheenginesgassupply.

Developmentofthedirect-actingfour-strokeengine

ForNikolausOtto,however,theimprovementoftheengineitself

wasmoreurgentthanthedevelopmentofanalternativesourceof

fuelusinggasoline,sincethedesignoftheatmosphericengine

limitedtheenginesoutputtoamaximumof3hp(2.2kW)aslong

asthedimensionshadtoremaininacontextthatcateredtothe

craftsandsmallbusinesses.Hot-airenginesbyother

manufacturersatthistimewerealreadyreachingupto8hp(5.9

kW).In1876,Ottothereforedevelopedadirect-actingfour-stroke

gasenginewithpre-compressionofthecharge,whichachieved3

hp(2.2kW)at180rpm.Intheprocess,headoptedtheflame

ignitionandslidevalvegearfromtheatmosphericgasengine.

WilhelmMaybachimprovedthisengine.Paralleltothe

developmentofthefour-strokeengine,atmosphericgasengines

werestillbeingbuiltinDeutz.Thelastoftheseengineswaspurchasedbyacustomeronlyafter1900.

In1877,NikolausOttowasgrantedGermanReichPatentNo.532


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forhisengine.Inparticular,hehadtheso-calledstratifiedcharge

patented:heassumedthatthesmoothanduniformignition

dependedonthedistributionofmixtureconcentrationinthe

cylinder.Ottomentionedhisrevolutionaryinventionofthefour-

strokeprocess,asisstillusedtoday,onlyunderItem4ofthe

patent.Hehadnotevenrecognizedthesignificanceofthis

inventionhimselfatthetime.

Multi-cylinderenginesbyDeutz

ThebasisforNikolausOttostwinenginein1879wastwo

parallel-mountedfour-strokesingle-cylinderenginesthathad

ignitionsdisplacedat360degrees,andthatactedtogetherona

crankshaft.Thisverysmoothlyrunningenginepoweredin

particulardynamosthatsuppliedelectricalenergyforlighting.

Inthesameyear,GottliebDaimlerdesignedtheDeutzcompound

engine,whichoperatedwithtwohigh-pressurecylindersandone

low-pressurecylinder.Inmechanicalterms,thisconstruction

correspondedtotheconnectingoftwofour-strokesingle-cylinder

unitswithonetwo-strokesingle-cylinder.Owingtoits

inefficiency,theoneenginethatwasdeliveredtoacustomerfor

testpurposeswasrepossessedbyDeutzin1884asunworkable,

andwasscrappedin1925.

Mobilityforthegasolineengine

Byaround1880,thegasolineenginewithflameignitionhad

becomeestablishedasastationaryengineformanyapplications.Thisinternalcombustionenginebecamethebasisofmodern

enginetechnology.However,itsusewasstillrestrictedto

stationaryoperation.Then,in1880,arailwaycarwitha


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stationarygasolineengineasdrivesystemwascreatedat

HannoverscheMaschinenbauAG(Hanomag).Theengine,

weighingapproximatelyoneton,hadalsobeenconvertedfrom

gastogasolineoperation,andwasmountedonatractorunitfor

streetcars.Forroadvehicles,however,the3-hp(2.2-kW)single-

cylinderenginewasstilltooheavy.

In1884,NikolausOttodevelopedamagneto-electriclow-voltage

impulseignitionforslow-runningstationaryengines.Thismade

operationwithgasolinesimpler,andaboveallsafer,thanwith

sparkignition.Althoughthisignitiondevicewasheavyand

expensive,itprovedtobeveryreliable.BecauseOttodidnot

patentthecontact-breakingignition,thetechnologywasalsoused

byrivalcompanies;forexample,Maybachsracingcarbuiltin

1900alsohadalow-voltageimpulseignition.


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CancellationofOttospatent

HanomagpursuedanactionforannulmentagainstOttospatent

forthefirsttimein1882.Hanomagsprincipalargumentwasthe

stratifiedchargeofthemixtureemphasizedbyOtto:thisalleged

prerequisiteforthesmoothrunningofafour-strokeenginehad,in

themeantime,beenfoundtobeincorrect.In1886,theSupreme

CourtoftheGermanReichfoundagainstNikolausOtto,andthe

patentwascancelled.Othercompaniescouldnowofficiallybuild

engineswithfour-andtwo-strokeworkingprocessesindesigns

thatwerepreviouslyprotectedbytheDeutzpatent.Thislegal

rulingalloweddramaticgrowthintheengineindustryinashort

periodoftime.

Ottospioneeringtechnologicalachievementsshouldinnowaybe

underestimatedfromamodernperspectiveasaresultofthelegal

rulingof1886.Withhisengine,heundoubtedlypavedthewayfor

developmentssuchastheDaimlerandBenzautomobiles,and

thesetwoautomotivepioneersthemselvesopenlybuilton

NikolausOttosworkastheywereconvincedofthetechnological

merits.Indoingso,fromthebeginning,Benzfocusedonthe

efficientintegrationofthedrivesystemintoaroadvehicle,while

Daimlerworkedprimarilyonauniversalenginewithwhichhe

soughttopowerasmanydifferentmeansoftransportaspossible.

Theideaofmobilitybymeansofthefour-strokegasolineengine

wasrealizedbybothpioneers,althoughtheirsolutionsdifferedin

theirdetails.

Manyyearslater,in1996,NikolausAugustOttoandWilhelmMaybachwerehonoredfortheirachievementsinengineeringand

automotivetechnology:thetwopioneerswereinductedintothe

AutomotiveHallofFame.


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CarlBenzandthehigh-speedfour-strokeengine

Benzpatentmotorcar:Single-cylinderwithelectricignitionVehicleswithhorizontally-opposedengineslaunchedin1897

Four-valvetechnologyinracingcarsCarlBenzhadprobablydecidedin1876tobuildaroadvehicle

drivenbyaninternalcombustionengine.Asitsdrivesystem,he

wantedtouseatwo-strokeengine,sincethefour-stroke

technologywasprotectedbyNikolausOttospatent.In1879,the

enginehadbeendevelopedtoastagewhereitrancontinuously.

TheBenztwo-strokeunitsweresoonverysuccessfulasstationary

engines.However,CarlBenzsbusinesspartnersinitiallyresisted

the(costly)developmentofvehicledrivesystems.Asaresult,

BenzleftGasmotoren-FabrikMannheim(MannheimGasEngine

Factory),andtogetherwithotherpartnersestablishedthe

companyBenz&Co.,RheinischeGasmotoren-Fabrik(RhenishGas

EngineFactory)in1883.

In1884,Benztookthegreatleaptowardsthehigh-speedengineforanautomobile.Now,hewantedtodevelopafour-stroke

enginetobeusedinhisvehicle.Benzstartedworkonthefour-

strokeengineinfall1884intheknowledgethatOttospatentwas

stillinforce.Thiswasstillthecasewhenhismotorcarcompleted

thefirstroadtestsonthefactorypremisesin1885.Thelegal

contextforDaimlersandMaybachsenginedevelopmentwas

similar,althoughBenzandDaimlerwerenotawareofeachothers

work.AtthetimethatCarlBenzdemonstratedhisautomobileinpublicin1886,Ottospatentwasbeingnullified.Nowtherecould

beopencompetitionforthemotorcarwithfour-strokeengine.


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Single-cylinderwithelectricignition

Fortheenginecreatedin1885,CarlBenzusedelectrichigh-

voltageignition.Thishummerignitiontheoreticallypermitted

higherenginespeedthanthehot-tubeignitioninventedby

Daimler.However,thisdidnotyetplayaroleinthefirstengines,

becausetheywerealongwayoffexhaustingtheengine-speed

potential.Usingadynamo,Benzobtainedtheelectricalenergyfor

theenginesusedforthefirsttimeinOctober1885intrialsinthe

Benzmotorcar.Becausethisearlyformofalternatordidnotwork

inasufficientlyreliablemannerunderroughroadconditions,

however,helaterdecidedtoinstallabattery.

InJanuary1886,Benzfiledthepatentapplicationforhismotor

car,andinNovemberofthesameyearhewasgrantedGerman

ReichPatentNo.37435forhisthree-wheeledvehiclewithgas-

fueledengine.Thewater-cooled,single-cylinder,four-stroke

enginedeveloped0.75hp(0.66kW)at400rpmfroma

displacementof954cubiccentimeters(bore90millimetersx

stroke150millimeters).Theintakeofthemixtureformedbya

surfacecarburetorwascontrolledbyanautomaticslidevalveand

theoutletbyaverticalpoppetvalveinthecylinderhead.

Forbettercooling,theenginehadanopencrankcase;together

withtheignitionandcarburetor,itweighed95.3kilograms.The

weightseemedparticularlyheavygiventhefiligreesteel-tube

constructionofthevehicleframe.Thesingle-cylinderenginewas

mountedhorizontallyabovetherearaxleandhadacrankshaft

runningverticallywithbalanceweightsandahorizontalflywheel.Inhispatentmotorcar,CarlBenzusedadifferentialinaroad

vehicleforthefirsttime.Thisallowedreliablesteeringofthe

three-wheelvehicle.


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Risingproductionfigures

In1888,BenzpresentedhismotorcarattheEngineandWorking

MachineExhibitioninMunich.Asalescontractforthecarwas

drawnup,butthedealwasnotclosed.Theinterestofapotential

customerneverthelessshowedthattherewasamarketforthe

newvehicles.Theimprovementoftheengineappearedtobean

opportunitytoexpandthemarket;thecompanyitselfwasalso

encouragingthis.Benz&Co.thuscommencedproductionof

marineenginesin1890.Theinnovationsimplementedinthese

in1893,Benzinstalledathrottlevalvebetweenthecarburetor

andengineinordertobeabletobettercontroltheoutputofthe

enginealsobenefitedcarengines.

Thecarenginesegmentinfactmadeuponlyasmallpartoftotal

productionatfirst.By1893,Benzhadbuiltatotalof1,000

gasolineengines,butfrom1886to1893only69automobileshad

beenbuilt.Automobileproductionthenincreasedsignificantly

from1894.Paralleltothis,theoutputoftheenginesalso

increasedfrom0.75hp(0.55kW)inpatentmotorcarmodelno.1

to3hp(2.2kW)fromtheone-literengineofthemostpowerful

patentmotorcarmodelno.3.

Innovationsforignitionandcooling

In1893,Benzinstalledanewignitionsystem.Insteadofthe

previoussolution,inwhichaprimarycircuitremained

permanentlyswitchedonandthebatterywasaccordinglydrained

quickly,theprimarycircuitwasnowswitchedononlyatatotalof70degreesofcrankrotation.Thatsavedenergyandalsoallowed

theintegrationofanignitionretard.Benzarrangedthisinsucha

waythatitcouldbeoperatedbymeansofaleverfromthedrivers


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seat.In1894,thenewenginefortheBenzVelo,amongstothers,

wasprovidedwiththisignitionretard.Theenginedeveloped1.5

hp(1.1kW)at450rpmfromadisplacementofalittleoverone

liter(110millimeterborex110millimeterstroke).TheBenzVelo

isconsideredtobetheworldsfirstseries-producedautomobile.

Withitshighproductionfiguresofapproximately1,200vehicles,

itthushelpedraiseBenz&Co.(from1899onwardsBenz&Cie.)

tothestatusoftheworldslargestautomobilemanufacturerinthe

yearsbefore1900.

Besidestheignition,coolingprovedtobeaproblemwiththe

increasingoutputoftheengines.Thus,Benzcooledthe5-hp(3.7-

kW)engineofhiscarwithacirculatingpump,forexample,when

thecirculationproducedbythethermo-siphonactionofthewater

wasnolongersufficient.From1895,thecoolingwasalsosupplied

withacondenserforcoolantrecovery,andlatertherewasfirstthe

finned-tuberadiator(1896),andthenthefinnedradiator(1903).

Enterthehorizontally-opposedpistonengine

Tenyearsaftertheinventionoftheautomobile,thepotentialof

thesingle-cylinderenginesforuseinpassengercarsappearedto

bestartingtodecline.Thesearchforamorepowerfuland,atthe

sametime,moresophisticatedengineinevitablyledtoengines

withseveralcylinders.In1897,CarlBenz,whoin1896hadsetup

aseparatedepartmentformotorvehicleproductioninhis

Mannheim-basedcompany,addressedthetaskofdesigningatwo-

cylinderengine.Thefirstprototypestillhadcylinderscoupledin

parallel,andhadsimilaritieswiththelaterin-lineengines.However,thetwinenginewasinitiallyonlyadesign,andBenz

insteadpursuedanalternativeconcept.


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Hedevelopedatwo-cylinderenginewithhorizontalcylinders,

whosepistonsworkinginoppositedirectionsactedonacommon

crankshaftandprovidedgoodbalancingofmasses.Benzcalled

thisengine,whichisknowntodayasahorizontally-opposed

pistonengine,thecontraengine,owingtotheopposingactionof

thepistons.Afirst4.2-litervariantwasinstalledinbusesasearly

as1898.However,themorematured1.7-literand2.7-liter

engineswereeventuallylaunchedin1899withoutputsof5hp(4

kW)and8hp(5.9kW),respectively,intheBenzDos--Dosmodel.

Thecontraengineprovidedmanyadvantagesoverin-lineengines.

Inparticular,thecylindersoffsetby180degreesbalancedthe

distributionofmassesverywell,becausetheirpowerstrokesin

opposingspatialalignmenttookplaceinanoffsetmannersuch

thatthemomentsofthepowerstrokeandintakestroke,andof

theexhauststrokeandcompressionstroke,wereoffsetbyone

another.Thismovementofthepistonswaspossiblethankstoa

double-offsetcrankshaft.Becauseofthisdoubleoffset,thetwo

cylinderswerearrangedslightlydisplacedrelativetooneanother

intheengineframe,whichwasopenatthetop.Thisconstruction

alsoallowedacompactandflatdesignofthehorizontally-opposed

pistonengine.

Theoutputofthecontraengineincreasedcontinuouslyafterits

launchin1899.Whilethe5-hp(3.7-kW)engineoftheDos--Dos

didnotchangeinitially,thelargervariantwith2.7-liter

displacementinitiallydeveloped8hp(5.9kW)in1899,then9hp

(6.6kW)in1900,andfinally10hp(7.4kW)in1901.Thetop-of-

the-lineengineamongtheproductionengineswasthe3.7-literenginewith20hp(14.7kW).Benzalsousedthehorizontally-

opposedpistonengineinracingcars.Thefinalstageofevolution

fortheMannheimracingcarswithacontraengineof1900


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likewisedeveloped20hp(14.7kW)afour-cylinderhorizontally-

opposedpistonenginewith5.4-literdisplacement.


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Two-andfour-cylinderin-lineengines

TheeraofthecontraengineatBenzcametoanendin1902.The

twinengineandanin-linefour-cylinderbasedonthiswerenow

installedinthenewParsifalmodelfromtheMannheimbrand.The

ParsifalmodelpresentedonOctober3,1902atthemotorshowin

Hamburghadanengineandpropellershaftinstalledatthefront.

Benz&Cie.thusfinallycompleteditsmoveawayfromtherear-

mountedengineandbeltdrive.Thepresentationtookplacein

DecemberattheParismotorshow,beforeaninternational

audience.

Thetwo-cylinderengineswereequippedwithspray-nozzle

carburetors,automaticintakevalves,side-mountedupright

exhaustvalvesandalateralcamshaft.Thelong-strokeengineshad

displacementsof1.5liter(8/10hpBenzParsifal)to2.3liter

(12/14hpBenzParsifal).Thetwo-cylindermodelrangewas

enhancedinthespringof1903withthefirstfour-cylinder

productioncarbyBenz.Unlikethethreeothervariants,the16/20

hpBenzParsifalwasprovidedwithchaindrive.Inthesameyear,

Benzpresentedthe35hpParsifalwithafour-cylinderengineand

adisplacementof5.9literasthetop-of-the-line-modelinthis

modelseries.Asanentry-levelvariant,theeight-hpParsifalwitha

one-litersingle-cylinderenginecompletedtherange.

Four-valvetechnologyforBenzracingcars

Benz&Cie.continuedtodevelopfour-valvetechnology.The

generationofBenzcarsaftertheParsifalhadengineswithdualignition,side-mounteduprightvalvesinaT-arrangementand

spray-nozzlecarburetors.Themodelsshownin1905rangedfrom

the18hpBenzwith3.2literdisplacementand18hp(13kW)at


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1400rpmtothe35/40hpBenzwith5.9literdisplacement,which

developeditsmaximumoutputof35to40hp(26kWto29kW)at

1350rpm.

Inthisperiod,thetwovariantsofaspecialtouringcarthatwere

producedforthe1910Prinz-Heinrich-Fahrt(PrinceHeinrich

Rally)representedanexceptionamongstBenzvehicles:inafirst

forBenz,theseengineswerefittedwithfourvalvespercylinder.

Boththe

5.8-literengine(80hp/59kWat2500rpm)andthe7.3-liter

engine(100hp/74kWat2500rpm)hadfouroverheadvalvesper

cylinderinaV-shapearrangement.Theintakeandexhaustvalves

weredrivenbymeansoftwolateralcamshafts.Despitethe

innovativetechnology,noneoftheBenzvehiclesreachedoneof

thetopthreepositionsinthecompetitionhostedbythePrussian

prince.ThemostsuccessfulBenzdriverwasFritzErle,who,with

an80hp(59kW)specialtouringcar,reachedfifthplace.

Afour-cylinderenginealsopoweredthe200hpBenz,therecord

carpopularlyknownastheLightningBenz.Theengine,weighing

407kilograms,developed200hp(147kW)at1600rpm.Ina

recordattemptontheBrooklandsracetrack,FritzErle,drivingthe

LightningBenz,exceededthe200km/hmarkforthefirsttimein

1909.Otherrecordsfollowed,andforseveralyearsthecarwas

thefastestvehicleintheworld.The21.5-literenginehadthe

largestdisplacementeverusedbyMercedes-Benzandits

predecessorbrandsinaracingorrecordcar.Larger

displacementswerefoundonlyinexperimentalandrecordcars

equippedwithfour-strokegasolineaircraftengines,forexamplethe92/160hpMercedeswithaDaimlerairshipengineof1917

(in-lineeight-cylinder,24-literdisplacement,160hp/118kW)

and,inparticular,theMercedes-BenzT80recordcarof1939,


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whoseDB602RSSpezialV12aircraftenginedeveloped3500hp

(2574kW)froma44.5-literdisplacement.


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Six-cylinderin-lineandaircraftengines

Benz&Cie.alsobuiltaircraftenginesbasedontheOttocycle:

theseincludedthe1912four-cylinderBenzFXaircraftengine

designedbyArthurBerger.In1913,aBenzFX9.6-literfour-

cylinderenginewitharatedoutputof105hp(77kW)wonthe

EmperorsprizeforthebestGermanaircraftengine.Thethird

placeinthecompetition,too,wenttoBenz&Cie.Inthefollowing

year,BenzbuilttheBzDVmodelGermanysfirstV12aircraft

engine.Theengine,weighing425kilogramsanddeveloping250

hp(184kW)froma20.3-literdisplacement,wasnotputinto

operation,however.Bycontrast,in1915,thefirstlargetwin-

enginedAEGairplanewasequippedwithBenzG-IVsix-cylinder

enginesoftheBzIImodel,withanoutputof150hp(110kW)

each.

Thesix-cylinderdesignalsofounditswayintoBenzautomobiles

in1914:the21/50hpBenzmodelwasthefirstpassengercar

fromtheMannheimbrandtohaveasix-cylinderin-lineengine.

Theenginehadcylindersarrangedinpairsanda5.3-liter

displacement,fromwhichitdevelopedanoutputof50hp(37kW)

at1650rpm.A6.5-literenginewith65hp(48kW)outputat1650

rpmlaterfollowedthesameprinciple.AftertheendoftheFirst

WorldWar,thefirstnewsix-cylindercarproducedbyBenzwas

the27/70hpmodelwithseven-literdisplacement,anoutputof70

hp(51kW)at1550rpm,anddualmagnetoignition.Beforethe

mergerwithDaimler-Motoren-Gesellschaftin1926,Benz

developedanothertwosix-cylinderengines.In1921,asix-

cylinderin-linewithtwosetsofthreecylinderseachwasproduced,andin1923asix-cylinderin-lineenginewithaone-

pieceengineblockfollowed.


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GottliebDaimler,WilhelmMaybachandthe

GrandfatherClock

Groundbreakinginventionsallowgreateroutputandreliability

FirsttestsintheRidingCarandmotorcarriage1897:Thefirstroadvehicleswithfour-cylinderenginesFollowingdifferencesofopinionwithNikolausOtto,Gottlieb

DaimlerandWilhelmMaybachresignedfromGasmotoren-Fabrik

DeutzonJune30,1882.InthesummerhouseofGottliebDaimlers

villainCannstatt,thetwomenworkedonahigh-speedand

lightweightfour-strokeengine.DaimlerandMaybachrealizedthisenginethefollowingyear.Theenginedevelopedapproximately

0.25hp(0.18kW)at600rpm.Thefirsttestswereundertaken

evenwithoutcooling,andwithgasoperation.Gradually,the

inventersprogressedtowardsthemodernengine,whichwasnot

fullyoperationaluntil1884.Becauseofitsshape,theenginewas

calledtheGrandfatherClock.

OnDecember16,1883,GottliebDaimlersoughtpatentprotectioninitiallyforthegasenginewithhot-tubeignitionandoneweek

laterfortheregulationofthespeedoftheenginethroughcontrol

oftheexhaustvalve(curvedgroovecontrol).Thisintermittent

controlwasregulatedbycentrifugalforce:arotatingtongueinthe

curvedgroovedeflectedthevalvecontrollinkageintheeventof

excessiveenginespeedinsuchawaythattheexhaustvalveno

longeropened.Theintakevalveofthenewenginewasstill

automaticallycontrolled,asitwasinOttosversion:itwasopenedbytheatmosphericpressurewhenthepistonstartedtheintake

stroke.Bothpatents,grantedonAugust4and27,1884asGerman


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basisforthefirsthigh-speed,four-strokeinternalcombustion

engine.

Carburetorsandhot-tubeignition

Fromtheoutset,DaimlerandMaybachfocusedongasoline

operationoftheengine.AtDeutzin1875,Maybachhadalready

gainedmuchexperienceinthepreparationofgasoline-air

mixtures.Gaswasnotactuallyproducedinthecarburetor,but

ratherafinemistoffueldroplets.ThefirstDaimlerengineswere

equippedwithafloat-typecarburetordesignedbyMaybach.

Daimlerretainedthistechnologyuntil1893whenthespray-

nozzlecarburetorwasintroduced.Thevisionarynatureof

WilhelmMaybachsenginedesignwasalreadyclearinaremark

from1884:evenatthisearlystage,Maybachwantedtoproduce

anintakemanifoldinjectionsystem.

Theprincipleofthehigh-speedgasolineengineforvehiclesbased

onOttosfour-strokeprinciplewasalreadyinevidencein1884in

theGrandfatherClock.Theenginewithhot-tubeignition,surface

carburetor,andairoverloadingviaavalveinthepistoncrown

developedanoutputofonehp(0.74kW)at600rpm.Suchhigh

enginespeedsbecamepossibleonlyforthegasolineengine,

thankstotheuncontrolledhot-tubeignitionwithanopenhot

tube,sincethistechnologyallowedanincreaseintheenginespeed

byafactoroffivecomparedwithopen-flameignitioninthegas

engine.

Initially,Daimlerplannedtousethehottubeonlyforstarting.However,becausethecompressionheatinthecylinderwasnot

sufficient,toignitethemixture,eveninthecaseofawarmed-up

engine,thehottubewaskeptred-hotbymeansofaburnerduring


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theentiredrivingtime.Daimlerlaterreflectedonthedevelopment

ofthisignitiondesign:Itwasalongroadrequiringcountlesstests

andtheuntiringsystematicworkofthepracticallyexperienced

engineer,soasnottogiveup[]inspiteoftheinitiallyaltogether

discouragingresultsofthesetests,[]until[]thecertaintyofthe

practicabilityofmyuncontrolledignitionhadbeenestablishedand

thegoalhadbeenachieved.

Theworldsfirstmotorcycle

In1885,DaimlerandMaybachfittedascaled-downversionofthe

GrandfatherClockintoawoodentwo-wheeler,theRidingCar.In

thiscar,theenginedeveloped0.5hp(0.37kW)at700rpm.With

thisdrivesystem,thedesignengineershadproventheirclaims

aboutlightweightconstructionandminiaturizationforamotor

vehicleinanimpressivemanner.Ofcourse,DaimlerandMaybach

didnothavetostartfromscratchinthisregard,since

incorporatedinthedevelopmentoftheenginewastheexperience

thatMaybachhadgainedwhenbuildingmodelenginesforDeutz.

InApril1885,GottliebDaimlerfiledapatentapplicationforan

enginewithaverticalcylinder,whichwasdevelopedfromthe

experimentalhorizontalengineof1883.Theengine,protected

undertheGermanReichPatentNo.34926,hadagroundbreaking

newdesign,inwhichthecrankassemblyandflywheelwere,for

thefirsttime,encasedinanoil-anddust-tightcrankcase.

InAugust1885,DaimlerthenpatentedtheRidingCar.Daimlers

youngersonAdolfundertookthemaidenjourneyofthis,theworldsfirstmotorcycle,fromCannstatttoUntertrkheim.The

RidingCarachievedspeedsofupto12km/h,butridecomfortwas

verypoor.Nevertheless,DaimlerandMaybachprovedthataroad-


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goingvehicle,freelycontrollablebyahumanbeing,couldbe

operatedwithaninternalcombustionenginethatobtainedits

powerfromgasoline.


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FromRidingCartomotorizedcarriage

Forhisfirstmotorcarin1886,Daimlerinstalledanengineina

coachframe.Inthefirstroadtests,anair-cooled0.5-hp(0.37-kW)

enginestillservedasthedrivesystem.Thefinalenginewasa

single-cylinderfour-strokeenginethathada70-millimeterbore

anda120-millimeterstroke.Withtheresulting462-cubic-

centimeterdisplacement,itdeveloped1.1hp(0.81kW)at650

rpm,whilethemaximumenginespeedwas900rpm.Theengine

hadaclosedcrankcase,overheadintakevalves,andvertical

tappet-controlledexhaustvalves,thehot-tubeignitionbasedon

theDaimlerpatentno.28022of1883,andasurfacecarburetor

basedonMaybachsfloat-typecarburetorsystem.Theengine

weighedonly40kilograms;theenginedevelopedindependently

byCarlBenzatthesametimewasmorethantwiceasheavy.This

lightweightdesignwaspossiblethankstothefiligree

construction:eventheDaimlerengineusedintheRidingCarhad

thinnerwallsthanhadbeenobtaineduntilthen,andwas

correspondinglylight.Thecasewascastinthebellfoundryand

fire-extinguisherfactoryofHeinrichKurtzinStuttgartthis

factorywasbetterequippedthanotherfoundriestodealwiththe

precisedimensionsrequired.

Gasolineengineforautomobilesandboats

Asaresultofthecontinuedpubliccriticismoftheuseofhighly

inflammablebenzeneasfuel,Daimlercalledhisengineapetrol

engine.Thisnamewasintendedtoevokepetroleum,which

peoplehadgreatertrustin.Therewaslessfearregardingshipsthatwereoperatedwithbenzene.Accordingly,Daimlerwassoon

equippingmotorboatswithhissingle-cylinderengine.InOctober

1886,hefiledapatentapplicationforamarineengine,andin


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1887wasgrantedGermanReichPatentNo.39367.

Atthesametime,thefirstmediawererecognizingthepotentialof

thenewdrivesystem.Thus,in1887,theUnitedStatesmagazine

TheWesthadmuchpraiseforDaimlersmotorcarriage.Thetext

inparticularportrayedtheengineasanoutstandingengineering

achievement:Inacarequippedwiththisdrivingpower,itwould

replacethepowerofhorses,whileinashipitwouldreplacethe

steamengine.Itsinestimablevalueliesinthefactthat,wherever

steam,electricityorgashadtobeprovideduntilnowtogenerate

power,suchasimpleandinexpensiveenginewithoutadditional

machineryorrequirementscouldbeusedtosatisfytheleastaswell

asthegreatestofdemands.

DaimlersV-engine

DaimlerandMaybachwerealsolookingforasolutionforthe

multi-cylindergasolineenginetoimprovepoweroutput.The

resultwastheworldsfirsttwo-cylinderV-engine,whichin1889

wasinstalledinthewirewheelcar.Theengine,developedin

1888,allowedDaimlertoreducethespecificengineweightfrom

80kilogramsto36kilogramsperhp.Inadditiontothewirewheel

car,theV-enginewasusedinboatsandrailwayvehicles,andalso

asastationaryengine.ThePanhard&LevassorandPeugeot

vehicles,whichscoredsuccessinthe1894Paris-Rouenrace,also

usedsuchengines.

Thenewenginewasconstructedlikethesingle-cylinder

GrandfatherClockenginesof1885:theclosedcrankcasewasalmostcompletelyoccupiedbythecrankwebsactingasflywheel

disks.Thetwocylindersformedanangleof17degreeswith

ignitionspacingof360degrees.Thus,onerotationequatedtoa


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completepowerstroke.Bothconnectingrodsactedonacommon

crankbend.Thecylinderheadwaswater-cooled,themixturewas

drawninthroughautomaticoverheadintakevalves,andthe

exhaustwasdischargedthroughcontrolleduprightexhaust

valves.

Daimlersoughtprotectionforthenewtwo-cylinderV-enginefrom

theGermanImperialPatentOfficein1889,andinFebruary1890

wasissuedwiththeGermanReichPatentNo.50839.Theversion

ofthe

V-engineinstalledinthewirewheelcarhadadisplacementof

565cubiccentimetersanddeveloped1.5hp(1.1kW)at700rpm.

Thenextgenerationalreadydeliveredtwohp(1.5kW)at620

rpm.

Atfirst,theV-enginestillhadtheoverflowvalvesknownfromthe

GrandfatherClockinthepistoncrown,whichtookcareof

overloadinginthecompressionstroke.Daimlerprobably

dispensedwiththatvalvearound1890.Oneofthereasonsfor

this,besidesthecomplexmechanics,wasthelowadditional

output,sincethecharginginthepistonhamperedtheoperationof

theuncontrolledintakevalve.Panhard&Levassorlikewise

decidedagainstthepistonvalvefortheirlicensedengines.

FrenchlicensesforDaimlerswirewheelcars

DaimlerdemonstratedthewirewheelcarindetailattheWorld

ExhibitioninParisin1889,whereaBenzpatentmotorcarwas

alsoshown.TheFrenchcompanyPanhard&LevassorboughtthelicensesfortheV-engineandthewirewheelcar.Theconclusionof

thiscontractisconsideredtohavesparkedthecreationofthe

Frenchmotorindustry.ByNovember1889,Panhard&Levassor


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hadalreadydeliveredthefirstenginebuiltinFranceunderthe

DaimlerlicensetoBarcelona,andthesecondunitfollowedin

December.

In1890,Panhard&Levassor,inturn,grantedthetoolandbicycle

factoryPeugeottherighttobuildenginesundertheirDaimler

license.ThePeugeotQuadricyclewasFrancesfirstfully

operationalroadvehiclewithaninternalcombustionengine.

Thewaytothefour-cylinderengine

In1889,WilhelmMaybachamongstotherthingsimprovedthe

suitabilityofDaimlerenginesforeverydayuse.Hethusundertook

testswithcoolantsthatweremixturesofwaterandglycerol,in

ordertoallowreliableoperationoftheengineevenat

temperaturesbelowminus10C(14F).

In1890,Maybachsfirstfour-cylinderin-lineenginewasalso

created.Thisenginewasusedonlyinboats,however.Theengine

developedfivehp(3.7kW)at620rpm.Thecylinderdimensions

were80millimeterborex120millimeterstroke.Withthisengine,

weighing153kilograms,Maybachhadproducedthearchetypeof

laterenginedesignseventhedrivesystemsoftodayarestill

basedonthefour-cylinder.Forthenewengine,Maybach

developedacrankshaftwithparallelbendsforcylinders1and4,

aswellas2and3.Theexhaustvalveswerecontrolledviaa

camshaft.

InAugust1890,forthefirsttime,afour-cylinderDaimlerenginewasdeliveredtoNewYorkasamarinedrivesystem.The451-

kilogramenginehadasix-literdisplacementanddeveloped12.3

hp(8.8kW)at390rpm.Tendayslater,Daimlerdelivereda


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secondmodelweighingonly153kilograms.Thissmallerboat

enginehada2.4-literdisplacementanddelivered5.9hp(3.7kW)

at620rpm.

TheSchroedterera

When,in1891,theargumentbetweenDaimlerandhisbusiness

partnersaboutthealignmentofthemodelrangeescalated,

GottliebDaimlerandWilhelmMaybachbothresignedfrom

Daimler-Motoren-Gesellschaft(DMG).Atthattime,DMGproduced

sevendifferentgasolineengines:thesingle-cylinderatonehp

(0.74kW),V2enginesat1.2andfourhp(0.74,1.5andthreekW),

aswellasaparalleltwo-cylinderdevelopingsixhp(4.4kW)

outputandthefour-cylinderunitsdevelopingaratedoutputof

fivehp(3.7kW)andtenhp(7.4kW),respectively.

MaxSchroedterbecamethenewchiefengineeratDMGfollowing

theresignationofDaimlerandMaybach.Heimmediately

developednewtwo-cylinderengineswithparallelcylinders.Such

engineswerealsoinstalledintheDaimlercarwithchaindrive,the

so-calledSchroedterCar,launchedin1892.OneofSchroedters

importantinnovationswastheregulationofthemixturefeedby

throttlingbymeansofapistonslidevalve.Overall,however,the

newenginesdidnotprovetobetechnicallymature.

MaybachsPhoenixengines

Atthesametime,Maybachcontinuedtodevelopnewvehicledrive

systems.Thework,whichwasinitiallycarriedoutinMaybachsownhomeandlaterintheformerHermannHotel,wasprivately

financedbyGottliebDaimler.Maybachsgreatestsuccessinthis

periodisconsideredtobethePhoenixengine.Thistwo-cylinder


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in-lineenginewasusedforthefirsttimein1895inthebelt-driven

car,afterDaimlerandMaybachhadreturnedtoDMG.Whenthe

1000thDaimlergasolineenginewasdeliveredinDecember1895,

theceremonywasonceagainheldinthegardenofGottlieb

Daimlersvilla.

Thecompanybowedtothepressureofthelicenseeswhorefused

furthercontractsunlessthetwodesignengineerswereonceagain

responsibleforthedevelopmentofnewproducts.Thisclearly

demonstratedDaimlersinternationalrenown.Amongstother

things,thiswastheresultofvictoriesinmotorracing:thefirst

automobileraceinhistoryisconsideredtohavebeenthe1894

ParisRouenraceorganizedbyPierreGiffard.Theoverall

winnersweremotorcarsbyPeugeotandbyPanhard&Levassor.

BothbrandsusedDaimlerenginesandachievedaveragespeedsof

approximately18km/h.In1895,aracefromParistoBordeaux

andbackwasagainwonbycarswithenginesby

Daimler/MaybachandbyBenz.

ThePhoenixenginewasusedinthebelt-drivencarwithoutputs

ofbetweentwohp(1.5kW)and7.5/eighthp(5.5/5.9kW)and

displacementsof760cubiccentimetersto2.2liters.Inplaceofthe

surfacecarburetorusedupuntilthen,Maybachsspray-nozzle

carburetor,developedin1893,nowprovidedthecarburetion.

Withthelatter,thedesignengineeranticipatedtheprincipleof

moderncarburetors.Maybachhadalreadylaidouthispreliminary

ideasforthespray-nozzlesystemin1891.Afterresigningfrom

DMG,heperfectedthecarburetorintheroomsoftheHermann

Hotel.Bythrottlingtheintakeairbymeansofanannulus,Maybachprovidedavacuumintheintakemanifold.Becausethe

gasolinewasunderatmosphericpressure,itwasforcedthrough

thenozzleintotheintakemanifold,andatomizedintoafinemist


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intheprocess.

Coolingwithflywheelandtubularradiators

In1892,Maybachalsoaddressedtheproblemofenginecooling.

Withtheincreasingoperationalreliabilityandoutputofthe

engines,effectivecoolingbecamemoreandmoreimportant.The

firstsolutionhedevelopedwasflywheelcooling.Here,thewarm

coolantwasroutedintoanopengroovethatwascastintotheedge

oftheflywheel.Aso-calledladlenozzlerecoveredthecooled

waterfromthisgroove.However,thesystemworkedonlyfor

engineswithuptofourhp(2.9kW)output.


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Thesolutionformoreeffectivecoolingwasthetubularradiator

whichMaybachconceivedin1897.Thisradiatorconsistedofaflat

waterboxwithopentubesinsidewhichwereexposedtothe

airflow.Afancoupledtotheengineshaftprovidedefficient

coolingevenintheidlemode.Thetubularradiatormadepossible

theconstructionofmuchmorepowerfulengines.

Thefirstroadvehicleswithfour-cylinderengines

In1897,DMGintroducedanewgenerationofmotorcarswhich

werethefirstDaimlerautomobilestohavefront-mounted

engines.Comparedwiththemotorcarriageswithbeltdrive,afirst

crucialstephadthusbeentakeninthedirectionofthemodern

automobile.ThefirstmodelwasdrivenbytheprovenPhoenix

two-cylinderengine.TheDaimlerautomobilealsotookitsname

fromtheengine:thePhoenixcar.

Theworldsfirstroadvehicleswithfour-cylinderengineswerethe

Phoenixcars,presentedin1898,withMaybachsnewfour-

cylinderin-lineengine.Thefirsttwounitsofthismodelwere

deliveredbyDMGtoEmilJellinekinSeptember1898.Theywere

drivenbyaneight-hp

(5.9-kW)2.1-literengine.During1899,DMGofferedother

variantsofthefirstseries-builtfour-cylindercarengine.The

outputrangedfromsixhp(4.4kW)to23hp(17kW).

Boschsmagnetoignition

In1897,theRobertBoschcompany,establishedin1886inStuttgart,developeditsnewcontact-breakingignitionbasedon

thewidelyusedimpulseignition.Thisignitiontechnologywas

lighterandworkedfasterthanitspredecessor.InJuly1898,abelt-


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drivenDaimlercarequippedwithBoschlow-voltagemagneto

ignitionsuccessfullyundertookafive-daytrialrunthroughthe

AustrianAlps.DMGalsotestedthenewsystemintrucks.Asa

resultoftheknowledgegained,thehot-tubeignitioncharacteristic

ofDaimlerenginedesignwasfinallyreplaced.

Despitethefastpaceofinnovationinthedevelopmentof

automobileengines,DMGdidnotlosesightofotherareasof

enginedesign.Thus,inFebruary1899,Daimlerequippedthe

airshipofCountZeppelinwithgasolineengines.Thefour-cylinder

light-alloyengine(Nseries)hada4.4-literdisplacementand

developed15hp(11kW)at700rpm.Themaidenflightofthe

LZ1airship,whichwaspoweredbytwoDaimlerengines,took

placeonJuly2,1900.

Historicalretrospective

In1899,theautomobileprogressivelybecamewidelyestablished

asanewmeansoftransport.Daimler-Motoren-Gesellschafttook

advantageofthissituationattheInternationalMotorShowin

Berlinthatyear,providingafirsthistoricalretrospectiveofthe

developmentsinenginedesigntodate.Inadditiontothelatest

automobiles,thefirstDaimlerenginesfrom1883weredisplayed.

Thisunderscoredtheinnovativeachievementsoftheprevious16

years.

Atthispoint,WilhelmMaybachwasalreadylookingtothefuture:

since1896,thedesignengineerhadbeencontinually

experimentingwithaluminumasamaterialforengineconstruction.Inamemo,hesummarizedthepositiveresultsofthe

1899teststhus:Asmuchaluminumaspossible.


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Controlledintakevalvesandhoneycombradiators

Maybachsenginedevelopedin1900forthe35hpMercedesagain

featuredseveralinnovations.Thus,theenginewithsix-liter

displacementandanoutputof35hp(26kW)at950rpmwas

fittedwithintakevalvesandexhaustvalvesthatwerecontrolled

viatwolateralcamshafts.Asaresultoftheconstructionwithtwo

valvesarrangedatthesides,theenginewasalsocalledthe

hammerengine.Forthefirsttime,Maybachalsoreplacedthe

tubularradiatorwithhisnewhoneycombradiatorinthismodel.

Itsconstructionwithnumeroustubesandasquarecross-section

maximizedthecoolingsurface,andmadeitpossibletouseless

waterinspiteofimprovedcoolingcapacity.

EmilJellinekorderedthisfirstMercedesinFebruary1900,andits

developmentwascompleteinDecember1900.Afterextensive

testingandrevision,inDecemberthenewvehiclewasdispatched

toJellinekinNice.Maybachhadonceagainoptimizedthe

lightweightconstructionoftheengineforthecar:thepower-to-

weightratiowas6.6kilogramsperhp,andwasthuslessthanhalf

ofthe23-hp(17-kW)engineof1898.Theundersquareengine

(116millimeterborex140millimeterstroke)madeoflightalloy

allowedthecaratopspeedofalmost90km/h.AttheNiceWeek

inMarch1901,Jellinekwonthreeracesinthe35hpMercedes.

MercedesSimplex

TheenginedesignofthefirstMercedesalsoinfluencedthedesign

oftheMercedesSimplexmodels.Theirfour-cylinderin-lineenginesdevelopedbetween32hp(24kW)at1200rpmwitha

5.3-literdisplacementand65hp(48kW)at1200rpmwitha9.3-

literdisplacement.The40hpMercedesSimplex,amoreadvanced


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developmentonthe35hpMercedes,wasagaindrivenbyEmil

Jellinekinthe1902NiceWeek.

ForthenewmodelsoftheSimplexseries(18/22hpmodel,60hp

sportscarand90hpracingcar)presentedin1903,Wilhelm

Maybachbuiltcompletelynewfour-cylinderengines.Thesehad

anoverheadintakevalveinthecenterofthecylinderandan

uprightexhaustvalvewhichwasoperatedbymeansofpushrods.

Inthecombustionzone,thecylinderswerecastwithdoublewalls

inorderforthecoolanttopassthroughmoreefficiently.

Boatengines,hybridvehiclesandsmallcars

Inadditiontothesenewautomobileengines,DMGpresenteda

300-hp(221-kW)six-cylindermarineenginefortheRussianNavy

in1902.Andthefollowingyear,theGermanboatMercedes,

equippedwithaMercedesSimplexenginewith40hp(29kW)

output,wonthefirstboatracefromParistothesea.Therace

coveredadistanceofmorethan322kilometers,andallsixstages

werewonbyMercedes.

In1902,FerdinandPorschewontheExelbergracewithahybrid

vehicleoftheMercedes-Lohner-Porschemodelinwhichthe

gasolineenginedrovetheelectricwheelhubmotorsbymeansofa

dynamo.TheprinciplewasalsousedbytheMercdsMixte

passengercarspresentedbytheAustrianDaimler-Motoren-

Gesellschaftin1906.Their45-hpor70-hp(33-kWor51-kW)

gasolineenginesdroveelectricwheelhubmotorsinthefront

wheelsbymeansofagenerator.

Experimentswithalternativedrivesystemsbasedonthegasoline

engineswerecommonatthetime.Thus,in1904,Maybachworked


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onagasoline-steamengine,whichwasintendedtotakeadvantage

oftheheatofthecoolantviaaheatexchanger.However,the

principledidnotwork.In1905,Maybachalsoabandonedtests

withpowertransmissionfromtheenginetotherearaxleby

meansofcompressedair.Thismethodwasintendedtodispense

withthetransmission,clutchanddifferential.Thecompressedair

producedbytheenginebymeansofapumpwasconvertedatthe

rearendintomovementbytwohorizontally-opposedpiston

engines.

PaulDaimlerdidnotattemptsuchadramaticbreakwiththe

designoftheSimplexinhisAustro-Daimlerof1903;thesmallcar

wasdrivenbyatransverselyinstalledtwo-cylinderenginewith

ninehp(6.6kW).

Six-cylinderbyMaybachandPaulDaimler

ThefinaldevelopmentoftheingeniousdesignengineerWilhelm

MaybachforDaimler-Motoren-Gesellschaftwasasix-cylinder

racingenginein1906.Maybacharrangeditscylindersindividually

onalight-alloycrankcase.Thecylinderlinersweremadeofsteel,

andthecylindershadoverheadintakeandexhaustvalvesthat

werecontrolledbymeansofcamshaftsandrockerarms.Each

cylinderwasequippedwithtwosparkplugsthatwere

independentofoneanother.Theoversquareengine(140

millimeterborex120millimeterstroke)developed106hp(78

kW)at1400rpmand120hp(88kW)at1500rpm.Itwasthe

archetypeformanylaterenginedesigns,includingaircraft

engines.

ParalleltoMaybachsracingengine,PaulDaimlerdevelopedasix-

cylinderin-lineengineforproductionvehiclesthenew37/65hp


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and39/75hpMercedesmodels.Inthe75-hp(55-kW)topmodel,

theenginehada10.2-literdisplacement.ThiscarbecameDMGs

firstproductionvehicletofeatureasix-cylinderengine.


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Frommodelyear1908,theMercedesvehiclesacquiredBosch

magnetosparkplugignitionsystems.DMGwasthefirst

manufacturertousethenewlow-voltageignitionsystemin

production,andoffereditscustomerstheoptionofretrofitting

olderengineswiththisnewsystem.Ignitionwasobtainedwitha

dualignitiondistributorandtwosparkplugspercylinder.This

madeitpossibletoignitethemixtureinparallelatdifferentpoints

ofthecylinder.Inhigh-performanceengines,thistechnology

prevailedforalongtime.

Thegasolineenginealsobecamethenormforcommercial

vehicles:in1910,theBreslaufirebrigadecommissionedthefirst

mobileturntableladderonaDaimlerchassiswithgasolineengine.

ItwasthusthefirstfireserviceinGermanytopossessafire-

fightingfleetmadeuponlyofmotorvehicleswithgasoline

engines.Allthreevehicles(motor-drivenfirepump,turntable

ladderandimplementcarrier)wereproducedona28/32-hp

chassisbyDaimlerMarienfelde.

TheeraoftheKnightsleevevalveengines

UnderPaulDaimler,whoin1907tookoveraschiefengineerof

DMGfromWilhelmMaybach,Daimler-Motoren-Gesellschaft

enteredintoapreliminaryagreementforthelicensed

manufactureofthevalve-freesleevevalveenginesofCharlesJ.

Knightin1909.AftertrialproductionofoneoftheAmerican

engines,in1910thedecisionwasmadetocommenceproduction

oftheseenginesforMercedesvehicles.Advantagesofthesleeve

valveengineincludeditsquietrunningandthepossibilityofobtaininghighenginespeedsofupto1600rpminfour-cylinder

engines.


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InDecember1910attheParisMotorShow,DMGwasalready

showingalandauletwithavalve-freeKnightsleevevalveengine.

Theproductionofa16/40hpMercedes-Knight(later

16/45Mercedes-Knight)beganinearly1911.However,theslide

valvegearprovedtobemechanicallyfragileandtoocomplexin

production.Intotal,onlyaround5500vehicleswithenginesofthe

Mercedes-Knighttypewereproduced.

Three-andfour-valvetechnology

The37/90hpMercedeswasthenewtop-of-the-linemodelof

DMGin1911.Itsfour-cylinderenginehada9.5-literdisplacement

andwasequippedwiththreevalvespercylinder(includingtwo

exhaustvalves)anddualignition.Thedesignmadeupofsingle

cylinderswithweldedcoolantjacketsreplacedthesix-cylinder

unitsproducedsince1907.

In1914,Daimler-Motoren-Gesellschaftalsosuccessfully

introducedmulti-valvetechnologyintheengineoftheGrandPrix

car.Thefour-cylinderin-lineunithadindividualuprightsteel

cylindersandcylinderheadsequallymadeofsteel.Ineachcase,

twointakeandexhaustvalveswerearrangedobliquelyinthe

countersunkroof-shapedcylinderhead.Ignitionoccurredwith

threesparkplugspercylinderhead.Thisengine,withitshigh

enginespeeds(105hp/77kWat3100rpm,maximumengine

speed3200rpm),becametheprototypeforaircraftenginesand

others.

Daimleraircraftengines

AircraftengineproductionhadalreadybegunatDMGin1909

withthecompletionofthefirst120-hp(88-kW)four-cylinder


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J4F.Inthesameyear,a30-hp(22-kW)B4Fandthefirstunitof

the60-hp(44-kW)four-cylinderD4Fwereproduced.In1913,

theMercedesDF80,a90-hp(66-kW)7.2-litersix-cylinder,took

secondplaceintheEmperorsprizeforthebestGermanaircraft

engine.

In1917,theSindelfingenplantwasalsocommissionedwiththe

manufactureofaircraftengines.Thoseinchargeoftheairforce

thusintendedtoboosttheproductionofMercedesaircraft

engines,whichuntilthenhadbeenconcentratedin

Untertrkheim,andatthesametimetodecentralizeit.InMarch

1918,thefirstSindelfingenworkshopsbeganaircraftengine

production.Inthefall,thenecessarytestbencheswereinstalled.

Owingtothelackofmachines,however,thefirstenginescouldnot

completetheirtestbenchrununtilshortlybeforetheendofthe

war.

Thesuperchargerera

Apowerfulhowlingnoiseannouncedthetriumphofanew

generationofsportyautomobiles:in1921,attheBerlinMotor

Show,DMGpresentedtheworldsfirstpassengercarwitha

superchargedengine.Theenginesofthefour-cylinder6/20hp

Mercedesand10/35hpMercedeswereprovidedwithairunder

excesspressurebymeansofadouble-bladedRootsblowerto

boostpoweroutput.Thetwocars,whoseoutputinthemeantime

hadonceagainbeenimproved,wentintoproductionin1923as

the6/25/40hpand10/40/65hpmodels.Inthemodel

designation,thefirstnumberdesignatedthetaxhorsepowerrating,thesecondtheengineoutputwithoutasupercharger,and

thethirdnumberdesignatedtheengineoutputwiththe

superchargerengaged.TheengineshadV-shapedoverhead


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valves,averticalshaft,andindividualsteelcylinders,andwere

combinedtoformablockinaweldedsheetsteeljacket.Thishigh-

performanceenginewasdesignedbyPaulDaimlerbasedonthe

exampleofaircraftenginesfromtheFirstWorldWar.The

technologyformechanicalchargingusingacompressoralso

originatedfromtheseaircraftengines.


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Initially,thefour-cylindermodelswith1.6-liter(6/25/40hp)and

2.6-liter(10/40/65hp)engineswereequippedwith

superchargers.Thesix-cylinderengineswithfour-liter

displacement(15/70/100hp)and6.2liters(24/100/140hp)

followed.AfterthemergerofBenz&Cie.withDaimler-Motoren-

Gesellschaftin1926,eventhelargeeight-cylindercars(380,

500K,540K,770)aswellasMercedes-Benzssportsandracing

carslikewiseacquiredsuperchargedengines.Themechanical

chargingnotonlyservedasameansofboostingoutput,butwas

alsoacharacteristicoftheprestigioushigh-performancevehicles

fromStuttgart.Thesuperchargerthusdefinedtheimageof

Mercedes-Benzwiththevaluesofperformance,innovationand

dynamism.

Evenbeforeseriesproductionofthesuperchargedcars,DMGhad

achievedracesuccesseswithmechanicallychargedvehicles.At

theTargaFlorioin1922,MaxSailerwasthewinnerinthe

productioncarcategoryina28/95hpmodelwhichwasequipped

fortheracewithasupercharger.TheTargaFlorio1922wasthe

firstraceinwhichsuperchargedcarswereentered.

AttheBerlinMotorShowinDecember1924,Daimlerpresented

thenew15/70/100hpand24/100/140hpMercedespassenger

carmodels.Thetwosuperchargedsix-cylindercarswould,in

future,serveastop-of-the-linemodelsinthesalesrange.

Thefirsteight-cylinderMercedes,andatthesametimethefirst

cardesignedbyFerdinandPorscheforDMG,wasthetwo-liter

Monzaracingcar.ThesuperchargedracingcarhaditsfirstracetheItalianGrandPrixinMonzainOctober1924.Porsches

designachievedgreatersuccessesonlyinvariousnationalraces,

and,asintheAVUSrace,inthefour-seatersportscarcategory.Its


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outputof170hp(125kW)at7000rpmallowedatopspeedof

180km/h.

TheMercedes-Benzgasolineenginefrom1926on

ReliableenginesguaranteedsatisfiedcustomersFirst-classperformanceandprestigewiththesuperchargerContinuedrefinementofdetailfeaturesAfterthemergerofDaimler-Motoren-GesellschaftwithBenz&Cie.

toformDaimler-Benzin1926,oldermodelsofbothbrands

continuedtobebuiltatfirst.Thefirstcompletelynewlydesigned

vehicleofthebrandwasthe5/25hpMercedes-Benzprototype

(W01series)withthesix-cylinderin-lineM01.Thisundersquare

enginewith1.4-literdisplacementwasdesignedbyFerdinand

Porsche.However,neitherthismodel,which,initsdisplacement

category,wasunusuallyrefined,northe5/25hpMercedes-Benz

(W14)witha1.3-literfour-cylinderM14engineevermadeitto

large-scaleproduction.

ThefirstnewlydevelopedMercedes-Benzproductioncarwasthereforethe8/38hpmodel(W02series)withthetwo-literin-

linesix-cylinderM02.Theveryundersquareengine(65

millimeterborex100millimeterstroke)developed38hp(28kW)

at3400rpm.ThiscarwasbasedonDMGsplansfora

superchargedtwo-litercar,and,followinganexchangeof

argumentationwithBenz&Cie.,itwasmodifiedandbecamea

vehiclewithamoresimpledesignforthesakeofhighproduction

figures.

Continuousdevelopment


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Themodelpresentedin1926didnotrepresentatechnical

milestoneinMercedes-Benzenginedevelopment.Instead,the

designengineersworkedfromaproventechnologicalbasisforthe

in-lineengine.Nevertheless,theM02hadgreatpotentialfor

futuredevelopment.Overaperiodoftwelveyears,andinseveral

stages,engineswithincreaseddisplacementevolvedfromthis

basisforsubsequentpassengercargenerations:forexample,the

M11ofthe2.6-litervariantsofthe1928Mercedes-BenzStuttgart,

theM182.9-literengineofthe1933Mercedes-Benz290(W18),

andfinallytheM142oftheMercedes-Benz320(W142I),

presentedin1937,witha

3.2-literengine,whichin1938wasincreasedto3.4liters.

Suchcontinuousdevelopmentofprovenenginesoveralong

periodoftimehasalwaysbeenresponsibleforthehighqualityof

Mercedes-Benzengines.Thepursuitofthesystematic

improvementofgoodproductsintheireverydetailwasthe

impetusforthistechnicalevolution.

FromMercedesKtoMercedes-BenzS

Takingupthethreadoftheshort,butglorioushistoryofthebig

Stuttgartsuperchargedsportscars,in1927Mercedes-Benz

launchedtheW06seriesofsuperchargedsportscars,beginning

withtheMercedes-BenzS(26/120/180hp)theSstandingfor

sport.

Anewchassiswasdeveloped,basedonthechassisofthe

DaimlerKmodel.TheMercedes-BenzSacquiredalowframe,andtheenginewasmovedbackwardsby30centimeters.Theaxleload

distributionwasthusimproved,andtheM06large-volumesix-

cylinderin-lineenginecouldbeinstalledmuchlower.TheM06


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hadadisplacementof6.8liters,owingtoenlargedbores.In

addition,majormodificationscomparedwiththeMercedesKwere

necessaryintheengineblock.Theengineersthuschangedfrom

drytowetcylinderliners;however,theenginestillhaddual

ignitionandtwosparkplugspercylinder,oneofwhich,ineach

case,wassuppliedbymeansofthetraditionalhigh-voltage

magnetoignitionandtheotherbymeansofbatteryignition.

Togetherwiththeupperpartofthecrankcase,thecylinderswere

castfromaluminum,andthecylinderheadwasmadeofgraycast

iron.Intakeandexhaustvalveswerearrangedoverheadinthe

cylinderhead,whilevalvecontrolwascarriedoutbyanoverhead

camshaft.Incombinationwithatwo-carburetorsystem,thenew

sportscarengineofficiallydeveloped180hp(132kW)witha

supercharger.Engineswithhighercompressiondevelopedupto

220hp(162kW)inracingwiththehelpofaspecialbenzene

mixtureasfuel.

ThefirstentryoftheMercedesBenzSintheGermanGrandPrixin

thesummerof1927resultedinatriplevictoryonthe

Nrburgring,withRudolfCaracciolatakingfirstplace.However,a

pressreleaseof1928alsoemphasizedthesuitabilityofthishigh-

performanceengineforeverydayuse:Theengineincontrastto

thesensitivitywhichissooftenfoundinraceenginesis

particularlypowerful,resilientandreliable,andbuiltforalong

servicelife,notjustforafewhoursofracingunderextreme

stresses.

FromStoSSKL

TheevolutionoftheMercedes-BenzSsportscartotheSSKL

occurredintheyearsafter1927,inparticularasaresultof

improvementstotheengines.TheSSmodelpresentedin1928


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hadanenginewitha

7-literdisplacement.Themaximumoutputwithasupercharger

wasinitially200hp(147kW)andcontinuallyincreasedto220hp

(162kW),then225hp(165kW),andultimately250hp(184kW).

Thesuperchargedenginewithamaximumenginespeedof3200

rpmwasconsideredalow-speedengine,sinceenginespeedsof

pureracingenginesofthetimeweremorethantwiceashigh.

TheSSthusofferedeitherahighlevelofcomfortwhentouringor

fullperformanceforracingpurposes.Mercedes-Benzalso

describedthecartopotentialbuyersintheseterms:[Thedriver]

nowusesthelesspowerfulormorepowerfulengineathisown

discretion,dependingonwhetherherequiresgreateracceleration

andtractivepowerforhisjourney.Generally,hewillonlyneedthe

superchargerinordertoreachthedesiredtravelingspeedmore

quickly,andthencontinueatthisspeedwithoutthesupercharger,

orhewillengagethesuperchargeronuphillstretcheswherehe

mustchangedowntothenextlowestgear,orwhicharetakenwith

theengineattoolowaspeed.Racingisadifferentstory.Here,one

alwaysdriveswiththesuperchargerengaged,unlesstheroad

characteristics(bends,etc.)prohibitthis.

TheW06serieswascompletedwiththeSSKandSSKLmodels.

TheSSKLracingsportscardeveloped300hp(220kW)fromits

7.1-literenginewithmechanicalcharging.Withthiscar,Rudolf

CaracciolaandWilhelmSebastianwontheMilleMigliain1931at

anaveragespeedof101.1km/h.Caracciolawasthusthefirstnon-

Italiandrivertowinthethousand-mileracewithstartandfinish

inBrescia.

ThefirstMercedes-Benzeight-cylinder


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In1928,the18/80hpMercedes-BenzNrburg460(W08)was

thefirstMercedes-Benzpassengercarwithaneight-cylinderin-

lineengine.Forthatreason,itwasalsocalledtheNrburg8in

somepublications,andthefrontcoveroftheearlycatalogwas

decoratedwithagold-embossednumber8surroundedbya

diamond.TheprestigiousvehiclewasdesignedbyFerdinand

Porsche.Hissuccessor,HansNibel,revisedtheW08afterjustone

year,andgavetheNrburgamoreelegantandsportierform.The

M08enginea4.6-litereight-cylinderin-lineunitremainedthe

same.Theenginewascontrolledbyalateralcamshaftand

developed80hp(59kW)at3400rpm.


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TheM07enginehaditspremierein1930asMercedes-Benzs

secondeight-cylinderengine,poweringthe770GrandMercedes.

Froma

7.7-literdisplacement,theenginedeveloped200hp(147kW)at

2800rpmwiththesuperchargerengaged.Themixturewas

providedbyaMercedes-Benzthree-nozzledoublecarburetor.The

W07wasineveryrespectaprestigiousvehiclethatsatisfiedthe

veryhighestdemands.Thetopspeedof160km/hwasperfectly

suitedtotherespectivedrivingconditions.

Innovativecompactcarwithrear-wheeldrive

Whiletheeight-cylindermodelsservedtoemphasizeMercedes-

Benzspositionintheluxuryclass,atthesametimetheengineers

wereworkingoninnovativeconceptsforcompactsedans.The

resultofthisresearchwasthe130(W23)modelof1934,whose

four-cylinderenginewith1.3-literdisplacementwashousedinthe

rearofthecar.ThismodelwasthusthefirstMercedes-Benz

passengercartohavearear-mountedengineasstandard.The

170H(W28)model,presentedin1936,alsohadafour-cylinder

gasolineenginemountedintherear.

Mercedes-Benzaircraftengines

ManyinnovationsinDaimler-Benzengineproductioninthe1930s

werebasedonaircraftengines.Thus,theLZ129Zeppelinairship,

betterknownastheHindenburg,wasdrivenbyfourDaimler-Benz

V16enginesfromtheDB602(LOF6)series,eachwitha

maximumoutputof1200hp(882kW).

In1937,theDB601A,aV12enginewithoverheadcylinders,went

intoproductionasthefirstDaimler-Benzaircraftenginewith


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gasolineinjection.UsingthemoreadvancedDB601ReVaircraft

engineintheMesserschmittMe209recordaircraft,in1939

aircraftcaptainFritzWendelachievedarecordspeedof755.138

km/h,whichwouldnotbebeatenfor30years.

Wartime

DuringtheSecondWorldWar,activitiestodevelopgasoline

enginesforpassengercarsatMercedes-Benzwereforthemost

partconfinedtoreactingtothedifficultsupplyconditions.In

1943,theStuttgartengineersthuspresentedawoodgas

generatorforthe170Vpassengercarthatweighedonly70

kilograms,cost800Reichmarksandcouldbeinstalledinoneday,

andwhichpermittedarangeofapproximately100to130

kilometerswithacharcoalloadof24kilograms.


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Mercedes-BenzgasolineenginesaftertheSecond

WorldWar

Firstcompletelynewdevelopments:six-cylinderenginesinmodels220and300

300SLcoupe:FirstproductioncarwithfuelinjectionFirstMercedes-BenzV8inthe600(W100)In1946,whenproductionwasresumedunderdifficultconditions

aftertheendofthewar,Mercedes-Benzfellbackonproven

enginesfromtheprewarrange.Thefirstpost-warpassengercar

enginebuiltinUntertrkheimwasa1.7-literfour-cylinderengine

forthe170V.

1951:Anewbeginning

Thefirstcompletelynewdesignstostartproductionaftertheend

ofthewarweretheenginesofthesix-cylinderMercedes-Benz220

(W187)and300(W186)passengercars.Bothcarswereshown

atthefirstFrankfurtInternationalMotorShow(IAA)in1951.

TheM180engineofthe220hada2.2-literdisplacementandan

outputof80hp(59kW).Theenginewasdesignedasatypical

oversquareenginewithanoverheadcamshaft,overheadvalvesin

thecylinderhead,andacrankshaftrunninginleadbronze

bearingswithnew,patentedmountingoftheweights.The

camshaftdrivewassilentandprovidedbyaDuplexrollerchain,

whilethemixturewasproducedbyaSolexdowndraftcarburetor.


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Mercedes-Benz300

Theforemostattention-grabberatthe1951IAA,however,wasthe

Mercedes-Benz300(W186).Atthetimeofitspresentation,this

modelwasthelargestandfastestproductioncarofalltheGerman

brands.Later,themodelwassimplycalledtheAdenauer,after

GermanFederalChancellorKonradAdenauerwholikedtobe

drivenintheMercedes-Benz300.Theoutputofthethree-liter

enginewasincreasedseveraltimesfrom1951:the115hp(85

kW)at4600rpmofthefirstW186Imodelwasfurtheradvanced

to125hp(92kW)at4500rpminthelastversionwiththe

M186IIengine.

Thepressreleasesaidoftheengineofthenewcar,theM186:[It]

representsnotonlythesumofthelastdecadesexperienceand

designknowledge,butalsoincorporatesconceptsthathadnotbeen

applieduntilnow.Oneexampleoftheseinnovationswasthe

oversquareenginedesignwithslowpistonspeed,whichresulted

inlesswearandalonglife.Anovelvalvearrangementallowed

largevalvecross-sectionsinspiteofasmallsurface,andpromoted

vortexformationinthecombustionchamber.Theignitionpoint

wasregulatedbymeansofacentrifugalgovernorandananeroid

capsuleintheintakemanifold,andinadditiontherewasthe

possibilityofprecisionadjustmentonthedashboard.

WiththeinstallationofthenewM189engineinthe300dmodel

(builtfrom1957to1962)withmanifoldinjection,theengine

outputwasagainincreasedto160hp(118kW)at5300rpm.

Anotherhigh-speedcarburetorengine,theM188,wasalreadyprovidedintheMercedes-Benz300S(W188I)coupein1951.

ThiswasreplacedbytheM199injectionenginein1955.The

engineoutputwasthusincreasedfrom150hp(110kW)at5000


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rpmto175hp(129kW)at5400rpm,whilethefuelconsumption

didnotchange.

ArrivaloftheMercedes-Benz300SL

TheMercedes-Benz300SLsportscarwasconceivedin1954

basedontheracingsportscarprototypepresentedin1952.The

coupewastheworldsfirstproductioncarwithafour-stroke

enginethatwasprovidedwithgasolineinjection.The300SL

featuredmechanicallycontrolleddirectinjectionviaaBoschsix-

plungerpump.Withthistechnology,theM198enginedeveloped

215hp(158kW)at5800rpm.Withtheenginedesignofthe

300SL,Mercedes-Benzsetthestandardsforthedevelopmentof

futuregenerationsofgasolineengines,justasitdidwiththeentire

sportscarconcept.The300SLroadsterpresentedin1957

retainedthisinjectiontechnology.In1962,however,thesix-

cylinderin-lineengineinstalledinclinedat45degreeswasfitted

withanewlight-alloyblock.

TheMercedes-Benz300dwasequippedwithafuelinjection

systemin1957.Inthiscase,however,Mercedes-Benzoptedfor

intermittentmanifoldinjection.Theinjectionagaintookplaceby

meansofaBoschsix-plungerpump.

TheMercedes-Benz220SE(W128)withtheM127Isix-cylinder

in-lineengineappearedin1958.Theinjectionsystemofthe2.2-

literenginewaspoweredbyaBoschtwo-plungerpump.The

enginedeveloped115hp(85kW)at4800rpm.Thetechnologyfor

increasingoutput,whichhadbeenestablishedformanyyearsalready,hadfinallybeenadoptedintolarge-scaleproductionwith

thismodel.Theadditionalcostcomparedwiththe220Smodel

withcarburetorenginewas1900deutschmarks.


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Gasolineenginesinthethree-boxbody

Agoodexampleofthedevelopmentofnewengineswithina

modelserieswastheMercedes-Benzwiththree-boxbody(with

self-supportingchassis-bodystructure,knownasPontonin

German).The180(W120)model,presentedin1953,hadan

M136IIfour-cylinderin-lineenginewith1.8-literdisplacement

forthefirstfouryears.Theenginedeveloped52hp(38kW)at

4000rpm.In1957,theenginewasreplacedbythenew1.9-liter

M121enginewhichalsopoweredthe190model.Insteadof

lateraluprightvalves,thecylindersnowhadoverheadvalves,

whilethelateralcamshaftwasreplacedwithanoverheadvariant.

Theoutputwasincreasedto68hp(50kW)at4400rpm,whileat

thesametimefuelconsumptionfellbyoneliterto10.5litersper

100kilometers.

Forthe1957modelyear,thesix-cylindermodels219(W105)and

220S(W180II)werefittedwithengineswithincreasedoutput

andtheHydrakhydraulic-automaticclutchasanoption.

Continuousdevelopmentofthefour-andsix-cylinderengines

Inthe1960s,innewmodelseriessuchastheTailfin,Mercedes-

Benzfocusedonthecontinuousdevelopmentofexistingengines.

The190(W110)modelwasthusfittedwiththelatestversionof

theM121engine.In1956,ithaddeveloped75hp(55kW)at

4600rpmandconsumed11.5litersofpremiumgasolineper100

kilometersinthe190(W121)model.Atthesameconsumption,

theoutputhadnowincreasedto80hp(59kW)at5000rpm,andthetopspeedwasapproximately150km/hinsteadof139km/h.

Thedesignersobtainedthisoptimizationinspiteofalargerand

heavierbodyworkwhichwasbuiltbasedonBlaBarnyis


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innovativeconceptformaximizingpassivesafety.

Thetop-of-the-linemodelinthisserieswasthe300SE(W112)

presentedattheIAAin1961.ItsM189injectionengineinitially

hadatwo-plungerinjectionpump,andfrom1964asix-plunger

pumpwasinstalled.Thankstomodificationsofthethree-liter

engine,theoutputwasincreasedfrom160hp(118kW)at5000

rpmto170hp(125kW)at5400rpm.Thefuelconsumptionofthe

carequippedwithautomatictransmissionasstandardchangedas

aresultofthemorepowerfulengine,whiletheincreasedtop

speeddidnot.

Mercedes-Benz600:Aclassapart

IntheMercedes-Benz600(W100),theStuttgartbrandpresented

aV8injectionengineforpassengercarsforthefirsttime.The

oversquareeight-cylinder(103millimeterborex95millimeter

stroke)enginedevelopedamaximumoutputof250hp(184kW)

at4000rpmfrom6.3liters.Togetherwiththeautomatic

transmissioninstalledasstandard,theW100hadaperformance

thatwouldalsohavedonecredittoasportscar:thesedan,

althoughweighingalmosttwo-and-a-halftons,achievedatop

speedofover205km/handacceleratedfromstandstillto100

km/hintenseconds.

Atthestartofplanning,theengineershadconsidereddesigning

theM100asafive-literengine.Thedecisiontoproducealight-

alloyV8wasmadeasearlyas1955.ParalleltotheM100,the

enginespecialistsalsoworkedonaV12engine,whichwasgiventhein-housecodeM101.Thisengine,whichwastohavea7.5-

literdisplacement,wasnotrealized,however.


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Finally,intheMercedes-Benz600,agroundbreakingenginewas

usedwithcylinderbanksmadeofgraycastiron,aluminum

cylinderheads,anda6.3-literdisplacement.TheinnovativeV8

engine,whicheasilyoutperformedcomparableenginesof

Americanbrandsintermsofoutputandrefinement,finally

becamethepowerhouseoftheMercedes-Benz300SEL6.3

(W109E63).Here,the250-hpenginewasresponsibleforthe

sedanstopspeedof221km/h.Enginepowerwastransferredto

theroadbyafour-speedautomatictransmission.

TheM100alsoinspiredthesmallerV8enginesofthe1970s:the

3.5-literM116enginewasemployedintheMercedes-Benz

300SEL3.5(W109E35/1)and280SE/SEL3.5(W108E35)

models.Theinjectionenginedeveloped200hp(147kW)at

5800rpm.Inaddition,theM117enginewith4.5-liter

displacementwasdevelopedforexporttoNorthAmerica.

Independentmid-series:TheStrokeEight

Inthefirstindependentmodelseriesofthemid-sizedcategory

(W115/114),Mercedes-Benzfocusedonprovenengine

technology.The200,220(W115),andthe230and250(W114)

modelshadin-linecarburetorengineswithoverheadvalvesand

anoverheadcamshaft.

InApril1972,the280and280Emodelswereaddedtothesedan

modelline-up.Bothwereequippedwithanewlydesigned2.8-liter

enginewithadoubleoverheadcamshaft.Thecarburetorversion

ofthisM110six-cylinderin-lineenginedeveloped160hp(118kW)at5500rpmandasaninjectionengine185hp(136kW)at

6000rpm.Sincethearrivalofthe280and280E,the250model

wasnolongerdeliveredwiththe2.5-literM114engine,but


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insteadwiththe2.8-literM130enginewhichwasalsousedinthe

280S(W108V28).IntheStrokeEight,aslightlyderatedvariant

wasusedthatdeveloped130hp(96kW)at5000rpminsteadof

140hp(103kW)at5200rpm.Theexportversionofthe250

modelfortheUSAandCanadahadbeenequippedwiththisengine

sinceJuly1970.

TheM110intheMercedes-Benz280hadV-shapedoverhead

valvesandtwooverheadcamshafts.Thecarburetorversion

createdthemixturewithadual-compounddowndraftcarburetor,

whilethe280Ehadanelectronicallycontrolledinjectionsystem

byBosch.Gasolineinjectionhadlongbeenestablishedinthe

Mercedes-BenzmodelrangewhentheStrokeEightwaslaunched:

the250,000thMercedes-Benzpassengercarwithaninjection

enginehadbeenbuiltintheSindelfingenplantin1969.

Mercedes-Benzdemonstratedfar-sightednessin1968withthe

presentationofanewfive-speedtransmissionforallcarswithsix-

cylinderengines.Demandwasstilllowatthetime,andproduction

wassuspendedagainin1976.Intheearly1980s,however,five-

speedtransmissionsweresuddenlyingreatdemandbecause

manymotoristswishedtoreducefuelconsumptionwiththis

moderntechnology.

ThreeV8enginesintheS-Class

TheMercedes-BenzS-Classofthe116series,presentedin1972,

wasofferedwithatotalofthreedifferentV8engines.The

280S/SEservedasentry-levelmodelwiththeM110ascarburetororinjectionengine(160hp/118kWand185hp/136

kW,respectively).Theoutputofthedual-camshaftenginechanged

betweenNovember1975andFebruary1976,whenthefuel-


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injectionsystemsofthe2.8-liter,3.5-literand4.5-literinjection

engineswereconverted.

Mercedes-BenzchangedfromtheelectronicallycontrolledBosch

D-Jetronictothenewlydeveloped,mechanicallycontrolledBosch

K-Jetronicinordertobeabletobetterconformtotheemissions

standardsthatinthemeantimehadbecomestricterinmost

Europeancountries.Inordertofacilitatemaintenance,thetwoV8

engineswereprovidedinthecontextofthesemeasureswith

contactlesstransistorizedignitionandhydraulicvalveclearance

compensation.Inallthreecases,theconversionwasinitially

associatedwithminoroutputlosses;fromApril1978,theoriginal

outputofthethreemodelswithmodifiedinjectionengineswas

againfullyavailable.

Inadditiontothe3.5-literV8M116andthe4.5-literM117engine

originallydesignedforNorthAmerica,inthe116seriesthe

V8M100,whichhadprovenitselfintheMercedes-Benz600,was

alsoused.Withanincreaseddisplacementofjustunder6.9liters

anddeveloping286hp(210kW)at4250rpm,itpoweredthetop-

of-the-lineMercedes-Benz450SEL6.9model.Thissedan,

presentedin1975,hadaK-Jetronicinjectionsystemcontrolledby

anairflowsensor.

Thetop-of-the-linemodelsinthe107seriesatthistimewerethe

Mercedes-Benz500SLroadsterandthe500SLCcoupeof1980.

TheywereequippedwiththeM117V8enginewitha

displacementofjustunderfiveliters,whichhadalreadybeen

employedinasimilarforminthe450SLC5.0of1978.

Launchofthe123serieswithanewsix-cylinderin-line

engine


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WhenMercedes-Benzlaunchedthenewmid-sized123seriesin

1976,theprovengasolineenginesofthe115/114serieswere

installedinthe200,230,280,and280E.OnlytheMercedes-Benz

250receivedacompletelynewlydevelopedsix-cylinderin-line

engine,theM123,witha2.5-literdisplacementandanoutputof

129hp(95kW)at5500rpm.Intheenginerangeofthe123series,

however,somechangesweremadeintheyearsfrom1978to

1980.Initially,inApril1978,theoutputofthe280Ewas

increasedto185hp(136kW)at5800rpm.InSeptember1979,

theoutputofthesix-cylindercarburetorengineinthe250was

boostedto140hp(103kW)at5500rpm.

InJune1980,Mercedes-Benzintroducedtwonewgasoline

engines:theM102two-litercarburetorenginedeveloping109hp

(80kW)at5200rpmandtheM102injectionengine,a2.3-liter

unitdeveloping136hp(100kW)at5100rpm.Thetwovariantsof

theM102replacedtheprovenenginesoftheM115series.The

all-newM102four-cylinderin-lineenginewasdesignedfor

installationatanangleinordertokeeptheoverallheightaslow

aspossible.Thisspecificationwasimportantsothattheengine

couldalsobeusedinfuturemodelgenerations.Thenewengines

outputhadbeenboostedby1525percentwhilefuel

consumptionwasuptotenpercentlower.

Theengineershadthusreachedthedevelopmentgoalforthe

M102,namelytocreatepowerreservesandimprovefuel

economy.Moreover,thesmoothoperationofthefour-cylinder

wasintendedtoapproximatethesix-cylinderin-lineengines.

Comparedwiththismorecomplexenginemodel,thefour-cylinderhadtheadvantagesofhightorque,inparticularintheimportant

lowerenginespeedrange,andhigherefficiencyasaresultofits

smallerfrictionlosses.Inthepressreleaseforthenewengine,


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Mercedes-Benzalsoemphasizedthat,intheM102,nostructural

experimentshadbeenmade,butinsteadtheenginerepresented

anoptimumcompromiseofalloftherequirementsforapassenger-

carenginethatwaseconomical,suitableforeverydayuse,and

reliable.

Thecylindersofthenewenginewereprovidedwithhemispheric

combustionchamberswithasquishlipinthecylinderhead.This

wasintendedtoguaranteemaximumswirltobeabletoignite

evenveryleanmixtures.Intakeandexhaustportsfacedeach

otherinaccordancewiththecross-flowprinciple.Tobeableto

increasetheexhaustports,sparkplugswithasizeofonly16

millimeterswereused.


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Endofjointproductionnetworkforgasolineanddiesel

engines

Tobuildagasolineengineoptimizedinthisway,Mercedes-Benz

hadtoabandontheintegratedproductionnetworkthathadbeen

partiallyestablishedbetweengasolinefour-cylindersanddiesel

passenger-carengines.Thisnetworkhaditsoriginsinthe1950s

andhadbeenestablishedagainstthebackgroundofmuchlower

productionfiguresatthetime.

Theconcentrationonengineblockspurelyforgasolineunits

allowedtheemploymentofveryprecisestructuralmeasuresfor

weightreduction.Thus,forthefour-cylinderin-lineengine,the

engineersdidnotuselightalloybutparticularlythinwall

thicknessesmadeofgraycastironinstead.UnlikeinV8engines,

lightalloywouldnothaveyieldedsuchsignificantweight

reductions.

V-enginesfortheW126S-Class

In1979,Mercedes-BenzpresentedthenewS-Class(W126series)

withtworevisedeight-cylinderengines.TheV8enginesofthe

predecessorserieswerereplacedbyengineswithincreased

displacementandalight-alloycrankcase.Thefive-literM117E50

enginethatreplacedthe4.5-litergraycast-ironenginehadalready

beenfittedinthe450SLC5.0.Theengineersdevelopedthe3.8-

literlight-alloyM116E38enginebasedontheexampleofthe

five-literenginefromtheveteran3.5-literV8withagraycast-iron

block.Owingtotheirhigheroutputatalowerweight,thenewV8enginesallowedimprovedperformancewithgreaterfuel

economy.Unchangedintherangewerethecarburetorversion

andtheinjectionversionofthe


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2.8-litersix-cylinder:thesewerebothprovenengineswithadual

camshaft.

In1981,aspartoftheMercedes-Benzenergyconceptforreducing

consumptionandpollutantemissions,thecompanythoroughly

revisedtheV8engines.Inadditiontoanincreaseincompression,

camshaftswithchangedvalvetiming,air-bathedinjectionvalves,

andelectronicidlingspeedcontrolfiguredonthelistof

improvements.Owingtothechangedcamshafttuning,the

maximumtorquecouldbeshiftedtolowerenginespeeds,andin

the3.8-literengineevenincreased.Thisengineunderwent

particularlyradicalchanges:inordertoachieveamorefavorable

volume-to-surfaceratio,theborewasreducedandthestroke

increased.Themodified3.8-literV8nowhadaslightlyincreased

displacement.

Inthetwoeight-cylinderengines,slightoutputlosseshadtobe

accepted,compensatingtosomeextentfortheconsiderably

improvedeconomicefficiency.Inthetwosix-cylinderengines,

therewasalsoarangeofdetailmodificationswithresulting

savings,althoughthesewerelesspronounced.Theoutput

potentialwasnotcompromisedasaresultofthesemeasures.

In1985,Mercedes-BenzpresentedacompletelyrevisedS-Class

line-upwithnewengines.Twonewlydesignedsix-cylinder

enginesreplacedtheprovenM110:insteadofthecarburetor

model,a

2.6-literinjectionengine(M103E26)wasnowused,whilethe

three-literM103E30engine,developedinparallel,succeededtheinjectionvariantsoftheM110.Alsonewtotherangewasthe4.2-

literV8M116E42enginewhichwascreatedbyenlargingthe

displacementofthe3.8-literengineandnowreplacedthe

Documents

MB Engine History