Determining maximum allowable refacing dimension
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- Insert valve and press it firmly against valve seat.
NOTE:
- If the valve is to be replaced as part of a repair, use a new valve for the calculation.
Fig 1: Measuring Distance Between Valve Stem End (Upper Edge) And Top Surface Of Cylinder Head Using Depth Gauge
- Measure distance - a - between end of valve stem and camshaft center axle (camshaft center axle is located at the level of cylinder head upper edge).
- Calculate maximum permissible refacing dimension from measured distance and the minimum dimension.
| Minimum dimension | ||
|---|---|---|
| Outer intake valves | Center intake valves | Exhaust valves |
| 39.3 mm | 41.0 mm | 39.9 mm |
Measured distance minus minimum dimension = max. permissible refaced dimension.
| Example for outer intake valve: | |||
|---|---|---|---|
| Measured distance | 39.7 mm | ||
| Minimum dimension | -39.3 mm | ||
| = | Maximum permissible refacing dimension | = 0.4 mm | |
NOTE:
- If the maximum allowed refaced dimension is 0 mm or less than 0 mm, repeat measurement using new valve. If measurement result is still 0 mm or less than 0 mm, replace cylinder head.