Procedures

STANDARD PROCEDURE - REFACING INTAKE AND EXHAUST VALVES

Special Tools:















The intake and exhaust valves have a 45.25 ± 0.25 degree face angle (1). The valve seats (2) have a 44.75 ± 0.25 degree face angle.

VALVES





Inspect the remaining margin (5) after the valves are refaced Specifications.

VALVE SEATS










NOTE: When refacing the valve seats, it is important that the correct size valve guide pilot be used for the reseating stones. A true and complete surface must be obtained.

1. Measure the concentricity of the valve seat using a dial indicator. Total runout should not exceed 0.050 mm (0.002 inch.) total indicator reading.
2. Inspect the valve seat (3) with Prussian blue to determine where the valve contacts the seat. To do this, coat the valve seat (3) LIGHTLY with Prussian blue then set the valve in place. Rotate the valve with light pressure. If the blue is transferred to the center of the valve face (4), contact is satisfactory. If the blue is transferred to the top edge of the valve face, then lower the valve seat with a 15 degree stone. If the blue is transferred to the bottom edge of the valve face, then raise the valve seat with a 65 degree stone.

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

3. When the seat is properly positioned the width of the intake seat should be 1.0 - 1.2 mm (0.04 - 0.05 in.) and the exhaust seats should be 1.41 - 1.61 mm (0.055 - 0.063 in.).

VALVE AND SPRING INSTALLED HEIGHT





1. Coat the valve stems (2) with clean engine oil and install the valves into the cylinder head.

NOTE: If the valves are being reused, reassemble them into their original locations.

2. If the valves or valve seats have been refinished, check the valve tip height (5). If the valve tip height (5) exceeds the specification, grind the valve tip until it is within specification Specifications. Make sure the measurement is taken from the cylinder head surface (7) to the top of the valve stem (2).





3. If removed, install the spring seat (3) and valve guide seal (1) over the valve guide Valve Guide Seals - Installation.

NOTE: Ensure that the garter spring (2) is intact around the top of the valve guide seal (1). Number 5 cylinder exhaust valve guide seal shown, all other valves similar.







NOTE: If the valve springs are being reused, reassemble them into their original locations. Number 5 cylinder exhaust valve spring shown, all other valves similar.

4. Install the valve spring (2) and valve spring retainer (1).






NOTE: Number 3 cylinder intake valve spring compression shown, all other valves similar.

5. Compress valve springs (3) with the Valve Spring Compressor Adapter (2) mounted in the Valve Spring Compressor (1). Install the retaining locks (4) and release the valve spring compression.





6. If the valves or valve seats have been refinished, check the installed height of the valve springs (4). If the installed valve spring height (4) is greater than 40.0 mm (1.575 in.), install a second spring seat (8) in the head counterbore under the valve spring seat (8) to bring the spring height back within specification. Make sure the measurement is taken from the top of spring seat (6) to the bottom surface of spring retainer (1).