Checking Valve Guide

Information 

Intake and outlet valves must not be reworked.

They can only be ground.

1. Check valves.
   1. 1.1  Check the stem and surface of valves for score marks.
   2. 1.2  If distinct score marks are visible:

      Replace valve.

2. > VAS 6079 - Dial gauge-2-  must be fitted.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Dial gauge on cylinder head

   1. 2.1  > VW387 - Universal dial gauge bracket-1-  must be fitted on the cylinder head.
   2. 2.2  > VAS 6079 - Dial gauge-2-  must be inserted in the > VW387 - universal dial gauge bracket-1-  .

   Information 

   If the valve is replaced during repairs, perform measurement using a new valve.

   Different valve stem diameters: Only use intake valves in the intake-valve guide and outlet valves in the outlet-valve guide.

3. Determine the valve tilt play.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Checking valve tilt play

   1. 3.1  Insert valve -1-  into the valve stem to be checked.

      The end of the valve stem must end flush with the valve guide.

   2. 3.2  Tilt the valve -1-  away from the dial gauge -2-  with your hand. -arrow A- 
   3. 3.3  > VAS 6079 - Dial gauge-2-  must be attached and set to zero.
   4. 3.4  Tilt the valve -1-  towards the > VAS 6079 - dial gauge-2-arrow B-  and determine the value.

      Wear limit: 0.7 mm for valve lift of 10 mm 

   5. 3.5  Repeat this on all valve guides to be checked.
4. If the wear limit is exceeded:

   Replace valves and repeat the measurement with new valves.

   Information 

   Valve guides cannot be replaced separately.

5. If the wear limit is still exceeded even with new valves.

   Replace cylinder head.