Valves, Springs, Seats, and Guides

CLEANING
Clean components using a suitable solvent.

INSPECTION





Fig. 132

1. Check valve stem tip for pitting or depression at point A (Fig. 132).
2. Check for wear and ridge wear at Point B.
3. Measure the clearance between the valve guide and valve stem. If the service limit is exceeded, replace the valve guides, valves or both.
4. Check for even contact (at face center) with valve seat, Point C.
5. Check margin. Refer to Engine Specifications. Replace valve if margin is out of specification.





Fig. 133

6. Check valve guide height (Fig. 133).
7. Measure valve stem to guide clearance. Refer to Engine Specifications.





Fig. 134

8. Measure valve spring free length and if the spring is square (Fig. 134). Refer to Engine Specifications.

VALVE SEAT INSPECTION





Fig. 135

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. 135).