Valve, Guide and Spring

Valve And Seat Angles (Part 1 Of 2):

Valve And Seat Angles (Part 2 Of 2):

The valve face and valve seat angles are shown in the illustration. Refer to Specifications for valve face and seat angles.
Inspect the remaining margin after the valves are refaced. Refer to Specifications.

VALVE SEATS

Valve Seat Refacing:

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 0.051 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 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 valve face, lower valve seat with a 30 degree stone. If the blue is transferred to the bottom edge of valve face raise valve seat with a 75 degrees stone.

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

4. When seat is properly positioned the width of both seats should be 1.02-1.52 mm (0.040-0.060 inch).

VALVE INSTALLATION
1. Coat valve stems with clean engine oil and insert them in cylinder head.

Valve Tip Height And Valve Spring Installed Height Measuring:

2. If valves or seats have been reground, check valve tip height (A) and valve spring installed height (B). If valve tip height is greater than 49.53 mm (1 61/64 inch) grind valve tip until within specifications. Make sure measurements is taken from cylinder head surface to the top of valve stem.

Valve, Spring, Seal And Retainer Installation:

3. Install valve spring seats over valve guides and new seals on all valve stems. Install valve springs, valve retainers.
4. Compress valve springs with a valve spring compressor install locks and release tool. If valves and/or seats are reground, measure the installed height of springs (B), make sure measurements are taken from top of spring seat to the bottom surface of spring retainer. If height is greater than 42.65 mm (1.670 inch), install a 0.794 mm (1/32 inch) spacer in head counter-bore under the valve spring seat to bring spring height back to 41.85-43.44 mm (1.648-1.710 inch).