36. Valve Guide Reaming, and Valve and Seat Grinding

- Tools Required
- J-42096 0.075 O.S. Valve Guide Reamer

VALVE GUIDE REAMING
Perform the following steps for reaming the valve guide.





1. Clean valve guide thoroughly.

IMPORTANT: Apply light hand pressure while turning the reamer until the reamer is all the way through the valve guide.

2. Insert J-42096 reamer into the valve guide from the top of the cylinder head.
3. Remove J-42096.
4. Clean valve guide of all metal shavings.
5. Clean cylinder combustion chamber of all metal shavings.

VALVE AND VALVE SEAT GRINDING

- Tools Required
- J-41775 Valve Spring Installer
- SA9102E-A Valve Spring Compressor Clamp





Seating of valves must he perform for engine assembly to deliver optimum power and to deliver optimum performance. Another important factor is the cooling of the valve heads. Good contact between each valve and its scat in the cylinder head is necessary to insure that heat in the valve head will be properly carried away.
Several different types of equipment are available for reconditioning valve seats. Carefully follow the equipment manufacturer recommendations to attain proper results. Regardless of what type of equipment is used, it is essential that valve guide bores be free from carbon and/or free from dirt to endure proper centering of the pilot in the guide.
Valves that are slightly pitted can be refaced to proper angle, insuring correct relation between head and stem, in a valve refacing mechanism. Replace valve stems which show excessive ware. Replace valves that are warped excessively. Replace the valve if the edge of the valve head is less than 1.6 mm (0.0625 inch) thick after grinding.
Use a 30° and a 60° stone to control valve seat width.





Grind the valves at a 90° 40' angle. Grind the valve seat at a 90° angle. The 40' difference in angles provides better sealing. The valve seat width should be:
- The intake valve seat width should be: 1.0 - 1.4 mm (0.039 - 0.055 inch).
- The exhaust valve seat width should be: 1.4 - 1.8 mm (0.055 - 0.070 inch).





6. Inspect valve springs:
a. Using calipers, measure the height of the valve spring at four locations. If the spring is bent, replace it.
Intake and Exhaust Valve Squareness:
Service Limit: 1.58 mm (0.1062 inch) max.





b. Using calipers, measure the free length of the valve spring. If the free length is not within specification, replace the valve spring.
Free Length:
Standard: 39.2 mm (1.543 inch) min.





c. Using a spring tester SA9183NE (or equivalent), fully collapse the spring three times, then measure the tension of the intake and exhaust valve springs at the specified installed length. If the installed tension is not as specified, replace the valve spring.
Standard: 34 mm (1.338 inch) at 252 N (56.6 lbs.)