Overhaul

Valve seats, refacing

Special tools, testers and auxiliary items required
^ Depth gauge
^ Valve seat refacing tool

Note:
^ When repairing engines with leaking valves, it is not sufficient to reface valve seats and replace valves. It is also necessary to check the valve guides for wear. This is particularly important on high mileage engines Valve guides, checking.
^ Only reface valve seats enough until a perfect contact pattern is obtained. Before refacing, determine maximum refacing dimension. If refaced dimension is exceeded, hydraulic valve lifter function is no longer guaranteed and cylinder head must be replaced.

Maximum permitted refacing dimension is calculated as follows:
- Insert valve and press firmly against seat.

Note: If the valve is to be replaced as part of a repair, use a new valve for the calculation.





- Measure gap - a - vertically between tip of valve stem end and upper edge of cylinder head - 1 -.
- Calculate max. permissible refacing dimension from measured distance and minimum dimension.

Minimum dimensions:
- Outer intake valves: 31.0 mm Center intake valve: 32.3 mm Exhaust valves: 31.9 mm

Measured distance - a - minus minimum dimension = max. permissible refaced dimension.








Refacing intake valve seat