Valve Grinding

1. Grind the valve only enough to remove pits and carbon.

CAUTION: If the valve head is cupped, replace the valve.





2. Check that the valve is ground to the correct valve face angle. Valve Face Angle (Intake and Exhaust): Standard: 44.75-45.25 degrees.





3. Check the valve head margin thickness. If the valve head margin thickness is less than minimum, replace the valve.
Intake:
^ Standard: 0.96-1.11 mm (0.0378-0.0496 inch).
^ Service Limit: 0.90 mm (0.035 inch) min.
Exhaust:
^ Standard: 1.12-1.27 mm (0.0441-0.0559 inch).
^ Service Limit: 1.00 mm (0.039 inch) min.





4. Check valve overall length. If the valve overall length is less than minimum, replace the valve. Overall Valve Length:
Intake:
^ Standard: 138.53-139.05 mm (5.45-5.47 inch).
^ Service Limit: 138.48-139.10 mm (5.4-5.48 inch).
Exhaust:
^ Standard: 138.73-139.25 mm (5.46-5.48 inch).
^ Service Limit: 138.68-139.30 mm (5.46-5.48 inch).

CAUTION: Do not grind off more than the minimum overall length.





5. Check the surface of the valve stem tip for wear. If the valve stem tip is worn, grind the valve stem tip with a valve grinder until flat. Replace the valve if necessary.