Case 770 EX - Page 48

Engine-Engineandcrankcase
Engine-Staticdescription
TheS8000isa4cylinderturbochargedandaftercooldieselengine.
Itfeaturesacrossowcylinderhead,withtheinletandexhaustmanifoldsonoppositesidesofthecylinderhead.
Thefuelandaircombustionprocess,takesplaceinthespeciallydesignedbowelinthecrownofthepistons.
Cylinderheadassembly
Thecylinderheadincorporatesvalvesandsprings,withthevalverockerarmshaftassemblyboltedtothecylinder
blockthroughthecylinderhead.
Cylinderheadretainingboltsareevenlyspacedwithasix-pointpatternaroundeachcylinder,thisensuresaneven
clampingloadacrossthecylinderhead.
Theintakeandexhaustmanifoldsareboltedtothehead,theintakemanifoldismountedontherightsideofthe
engine,withthedieselinjectorsmountedoutsidetherockercover.
Theexhaustmanifoldismountedontheleftsideoftheengine.
Wateroutletconnectionsandthermostatbeingattachedtothefrontofthecylinderblockdirectlybehindtheradiator
valveguidesareinsertedintothecylinderhead,andreplaceable.
Specialreplaceablecastalloyvalveseatsarepressedintoeachvalveportduringmanufacturing.
Nooversizevalveseatsonguidesareavailable.Allvalvesarettedwithpositivevaluerotators,valveclearanceis
maintainedbyadjustmentoftheselflockingadjustingscrew,mountedineachoftherockerarms.
Camshaftassembly
Thecamshaftrunsin3replaceablebushes.
Thecamshaftdrivegearisinmeshwithanddrivenbythecamshaftidlergearwhichisdrivenbythecrankshafttiming
gear.
Camshaftendthrustiscontrolledbyathrustplateboltedtotheblock,andlocatedbetweenthecamshaftgearand
thefrontcamshaftjournal.
Cylinderblockassembly
Thecylinderblockisanalloycastironwithdeepcylinderskirts&waterjacketsforcoolingthecylinders.
Thecylinderboresaremachinedintegralwiththecylinderblock,duringthemanufacturingprocess.
Cylindersareinline,verticalandnumbered1to4fromradiatortotheenginerear.
Theoilsump,whichisattachedtothebottomofthecylinderblock,isthereservoirfortheengineoillubricationsystem.
Acastironenginefrontcoverandfrontplateisattachedtothefrontoftheengineandcoversallofthetiminggear
assembly.
Crankshaftassembly
Thecrankshaftissupportedinthecylinderblockby5mainbearingsin76Hp/86Hpengines.
Thecrankshaftismanufacturedfromsteelwithmachinednishedcrankwebs.Endthrustiscontrolledbyathrust
bearingincorporatedinthecentermainbearingofthecrankshaft.
Connectingrods
Connectingrods“wedge”shapedatthesmallendhasbeendesignedtoreducethereciprocatingweightatthepiston
end.
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