Valve and Valve Seat Refacing

VALVE AND VALVE SEAT REFACING

Refer to Engine Specifications for the valve face and valve seat angles Engine Specifications.

VALVES










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

VALVE SEATS

1. When refacing valve seats, it is important that the correct size valve guide pilot be used for re-seating stones. A true and complete surface must be obtained.
2. Measure the concentricity of valve seat using dial indicator. Total runout should not exceed 0.051 mm (0.002 inch.) 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, then lower valve seat with a 15 degree stone. If the blue is transferred to the bottom edge of valve face, then raise valve seat with a 65 degree stone.

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

4. When seat is properly positioned, the width of the intake seats should be 0.75 to 1.25 mm (0.0296 to 0.0493 in.) and exhaust seats should be 1.25 to 1.75 mm (0.049 to 0.069 in.).

VALVE AND SPRING INSTALLED HEIGHT










1. Coat valve stems with clean engine oil and insert the valves into the cylinder head.
2. If valves or seats have been refaced, check valve tip height (A). If valve tip height is greater than 43.65 mm (1.7185 in.) intake or 45.98 mm (1.8102 in.) exhaust, grind valve tip until within specifications. Make sure measurement is taken from cylinder head surface to the top of valve stem.










3. Install valve seal/spring seat assembly over valve guides on all valve stems. Ensure that the garter spring is intact around the top of the valve seal.
4. Place valve spring (color-coded end facing up) and valve retainer into position on spring seat.
5. Compress valve springs with valve spring compressor C-3422-D and adapter 6526A Tools and Equipment, install locks and release tool.










6. If valves and/or seats are refaced, measure the installed height of springs. Measurements are taken from top of spring seat to the bottom surface of spring retainer. If height is greater than 38.75 mm (1.5256 in.), install a 0.762 mm (0.030 in.) spacer in head counterbore under the valve spring seat to bring spring height back within specification.