Valve and Valve Seat-Refacing

Fig. 25

1. With suitable valve spring compressor, remove spring retainer locks, retainer, valve spring, spring seat and valve (Fig. 25).





Fig. 26

2. Remove valve stem seals with suitable tool (Fig. 26). Do not reuse valve stem seals.

VALVES





Fig. 27

1. Check valve stem tip for pitting or depression at point A (Fig. 27).
2. Check for wear and ridge wear at Point B.
3. Check for even contact (at face center) with valve seat, Point C.
4. Check margin (Fig. 27). Replace valve if margin is out of specification. Refer to Engine Specifications.





Fig. 28

5. Check valve guide height (Fig. 28).
6. Measure valve stem to guide clearance. Refer to Engine Specifications.





Fig. 29

7. Measure valve spring free length and squareness (Fig. 29). Refer to Engine Specifications.

VALVE SEAT





Fig. 30

Inspect the valve seat with Prussian blue to determine where the valve contacts the seat. To do this, coat valve seat LIGHTLY with Prussian blue then set valve in place. Rotate the valve with light pressure. If the blue is transferred to the center of valve face, contact is satisfactory. If the blue is transferred to top edge of the valve face, lower valve seat with a 15 degrees stone. If the blue is transferred to the bottom edge of valve face raise valve seat with a 65 degree stone (Fig. 30).

INSTALLATION
1. Install valve spring seat.





Fig. 31

2. Using suitable tool install seal by tapping lightly until seal is in place (Fig. 31).





Fig. 32

3. Install valve spring with the enamelled ends facing the rocker arms (Fig. 32).

CAUTION: During reassembly, compressing the valve spring more than necessary to install valve spring retainer locks can cause the retainer to be forced against the stem seal and damaging it.