Refacing In General

Refacing In General

NOTE: When repairing engines with leaky valves, it is not sufficient to merely replace the valves and machine the seats. The valve guides must also be checked for wear; a condition that increases with higher mileage.

Only rework the valve faces enough to achieve a suitable contact. Calculate the maximum permissible refacing dimension before refacing.

If the refacing dimension is exceeded, proper function of the hydraulic lifter will not be assured and the cylinder head will have to be replaced.







- Insert valve into guide and push firmly into seat

- If the valve is replaced in the course of repairs, use a new valve for measuring.

- Measure the distance between the end of the valve (stem) and the machined upper edge of the cylinder head

- The maximum permissible refacing dimension If the refacing dimension is exceeded, proper lifter function will not be assured and the cylinder head will have to be replaced.

- Minimum dimension:
Intake valve 34.4 mm
Exhaust valve 34.7 mm

The measured distance minus the minimum dimension will yield the maximum permissible refacing dimension

Example
Measured distance 35.1 mm
Minus minimum dimension 34.4 mm
= maximum permissible refacing dimension 0.7 mm