Valve and Valve Seat Refacing

VALVE AND VALVE SEAT - REFACING





The intake and exhaust valves have a 44°- 44.5° face angle (1). The valve seats (2) have a 44.75° - 45.25° face angle.

Inspect the remaining margin after the valves are refaced. Engine Specifications.

VALVE SEATS





CAUTION: Do not un-shroud valves during valve seat refacing.

1. When refacing valve seats, it is important that the correct size valve guide pilot be used for reseating stones. A true and complete surface must be obtained.
2. Measure the concentricity of valve seat using a dial indicator. Total runout should not exceed 0.05 mm (0.002 in.) total indicator reading.
3. Inspect the valve seat with Prussian blue to determine where the valve contacts the seat. To do this, coat valve seat LIGHTLYwith 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 valve face, lower valve seat with a 30° stone. If the blue is transferred to the bottom edge of valve face raise valve seat with a 75° stone.

NOTE: Valve seats which are worn can be reworked, provided that correct angle and seat width are maintained. Otherwise cylinder head must be replaced.

4. Measure valve seat width after refacing 1.02 - 1.52 mm (0.040 - 0.060 in.).