Valve Guide Servicing

With dial indicator, measure amount of clearance between valve and guide with end of stem flush with guide. If wear exceeds limits of 0.032" (0.8 mm) for intake, or 0.039" (1.0 mm) for exhaust, replace valve guides.

Fig 1: Measuring Valve Guide Clearance
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
Press worn guide out from combustion chamber side. Place circlip into groove of replacement guide and press new guide in from camshaft side. Production guides do not have circlips and may be smooth or have one groove. Replacement guides have a circlip in addition to 1 or 2 grooves on camshaft end.

Ream replacement guide by hand with dry reamer for proper clearance. Change valve spring retainer resting on head to replacement type with groove.

VALVE GUIDES

Fig 2: Replacement Valve Guide and Intake Spring Retainer

Courtesy of PORSCHE CARS NORTH AMERICA, INC.