RECONDITIONING CYLINDER HEADS Chapter 9 Page 209 Classroom Manual Page 207 Lab Manual RKRKRKRK

Page CHAPTER OBJECTIVE n n Correct valve guide clearance by: Knurling. Reaming to accept oversize valve stems. Installing bronze guide liners. Installing cast iron guide inserts. n n Replace intregal and insert valve seats. n n Grind valve seats & correct contact pattern. RKRKRKRK

Page CHAPTER OBJECTIVE n n Recondition valve faces & tips. n n Identify proper valve face-to-seat contact pattern. n n Correct valve stem seal alignment. n n Replace worn or damaged pressed-in rocker arm studs with oversize and threaded studs. n n Resurface cylinder head sealing surface. RKRKRKRK

CHAPTER OBJECTIVE u u Measure & correct valve guide height. u u Measure & correct valve spring installed height. u u Measure & correct valve stem height.

Page INTRODUCTION n n Valve guide repair. n n Reconditioning valve guides. n n Grinding valves. n n Reconditioning valve seats. n n Resurfacing cylinder head. RKRKRKRK

Page RESURFACING THE HEAD * * Types of resurfacing equipment Belt sander Surface grinder Rotory broach n n The amount of material removed, each pass, depends on the type of equipment used. n n Resurfacing increases compression ratio. RKRKRKRK

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

MANIFOLD ANGLES

SURFACE FINISH n n The rougher the surface thehigher the microinch finish.

COMPRESSION RATIO n Combustion chamber volume n Head gasket volume n Deck Height n Cylinder volume

Terms n Radius = diameter /2 n Squared = number multiplied by itself n Pi = n Stroke = Piston movement TDC to BDC

COMBUSTION CHAMBER n Measure combustion chamber in cc’s

HEAD GASKET n Figure head gasket volume n Use formula Pi x radius 2 x height n Convert to cc’s, ci x = cc

DECK HEIGHT n Bring piston to TDC n Measure from deck to piston n Figure area Pi x r 2 x height

CYLINDER VOLUME n Bore divided by 2 n Pi r 2 x stroke

CLEARANCE VOLUME AT TDC n Combustion chamber volume in cc’s n Head gasket volume in cc’s n Deck height volume in cc’s ______ n Total

CLEARANCE VOLUME AT BDC n Combustion chamber volume in cc’s n Head gasket volume in cc’s n Deck height volume in cc’s n Cylinder volume in cc’s ______ n Total

COMPRESSION RATIO n Clearance volume at TDC ________________________ = CR n Clearance volume at BDC