RECONDITIONING CYLINDER HEADS

RECONDITIONING CYLINDER RECONDITIONING CYLINDER HEADSHEADS

Chapter 9Chapter 9Page 209 Classroom

ManualPage 207 Lab Manual

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CHAPTER OBJECTIVECHAPTER OBJECTIVE

Correct valve guide clearance by:• Knurling.• Reaming to accept oversize valve stems.• Installing bronze guide liners.• Installing cast iron guide inserts.

Replace intregal and insert valve seats. Grind valve seats & correct contact

pattern.

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CHAPTER OBJECTIVECHAPTER OBJECTIVE

Recondition valve faces & tips. Identify proper valve face-to-seat contact

pattern. Correct valve stem seal alignment. Replace worn or damaged pressed-in

rocker arm studs with oversize and threaded studs.

Resurface cylinder head sealing surface.

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CHAPTER OBJECTIVECHAPTER OBJECTIVE

Measure & correct valve guide height. Measure & correct valve spring installed

height. Measure & correct valve stem height.

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INTRODUCTIONINTRODUCTION

Valve guide repair. Reconditioning valve guides. Grinding valves. Reconditioning valve seats. Resurfacing cylinder head.

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RESURFACING THE HEADRESURFACING THE HEAD

Types of resurfacing equipment• Belt sander• Surface grinder• Rotory broach

The amount of material removed, each pass, depends on the type of equipment used.

Resurfacing increases compression ratio.

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RESURFACING CONCERNSRESURFACING CONCERNS

Spark Knock . Piston-to-valve interference. Change in rocker arm geometry. Change in clearance volume. Misalignment of the intake manifold. Inaccurate cam timing on OHC engines. Surface finish.

MANIFOLD ANGLESMANIFOLD ANGLES

SURFACE FINISHSURFACE FINISH

The rougher the surface thehigher the microinch finish.

COMPRESSION RATIOCOMPRESSION RATIO

Combustion chamber volumeCombustion chamber volume Head gasket volumeHead gasket volume Deck HeightDeck Height Cylinder volumeCylinder volume

TermsTerms

Radius = diameter /2Radius = diameter /2 Squared = number multiplied by itselfSquared = number multiplied by itself Pi = 3.1416Pi = 3.1416 Stroke = Piston movement TDC to BDCStroke = Piston movement TDC to BDC

COMBUSTION CHAMBERCOMBUSTION CHAMBER

Measure combustion chamber in cc’sMeasure combustion chamber in cc’s

HEAD GASKETHEAD GASKET

Figure head gasket volumeFigure head gasket volume Use formula Pi x radiusUse formula Pi x radius2 2 x heightx height Convert to cc’s, ci x 16.3866 = ccConvert to cc’s, ci x 16.3866 = cc

DECK HEIGHTDECK HEIGHT

Bring piston to TDCBring piston to TDC Measure from deck to pistonMeasure from deck to piston Figure area Pi x rFigure area Pi x r22 x height x height

CYLINDER VOLUMECYLINDER VOLUME

Bore divided by 2Bore divided by 2 Pi rPi r22 x stroke x stroke

CLEARANCE VOLUME AT CLEARANCE VOLUME AT TDCTDC

Combustion chamber volume in cc’s Combustion chamber volume in cc’s Head gasket volume in cc’s Head gasket volume in cc’s Deck height volume in cc’s Deck height volume in cc’s

____________ TotalTotal

CLEARANCE VOLUME AT CLEARANCE VOLUME AT BDCBDC

Combustion chamber volume in cc’s Combustion chamber volume in cc’s Head gasket volume in cc’s Head gasket volume in cc’s Deck height volume in cc’s Deck height volume in cc’s Cylinder volume in cc’s Cylinder volume in cc’s

____________ TotalTotal

COMPRESSION RATIOCOMPRESSION RATIO

Clearance volume at TDCClearance volume at TDC________________________ = CR________________________ = CR Clearance volume at BDCClearance volume at BDC