Range Rover (LH) V8-3.9L (1989)
Valve Seat: Service and Repair
Replacement
Valve Seats
1. Check the valve seats for wear, pits and burning and fit new inserts if necessary.
2. Remove the old seat inserts by grinding them away until they are thin enough to be cracked and pried out.
3. Heat the cylinder head evenly to approximately 65°C (150°F).
4. Press the new insert into the recess in the cylinder head.
NOTE: Service valve seat inserts are available in two over-sizes 0.25 and 0.50 mm (0.010 and 0.020 in) larger on the outside diameter to ensure
interference fit.
Valve Seats
5. Using service tool MS621 if necessary, cut the valve seats to 46 ± 1/4°.
6. The nominal seat width is 1.5 mm (0.059 in). If the seat exceeds 2.0 mm (0.078 in) it should be reduced to the specified width by the use of 200
and 700 cutters.
7. The inlet valve seat diameter: A is 37.03 mm (1.458 in) and the exhaust valve seat is 31.50 mm (1.240).
Valve Seat Cutter
8. Ensure that the cutter blades are correctly fitted to the cutter head with the angled end of the blade downwards facing the work, as illustrated.
Check that the cutter blades are adjusted so that the middle of the blade contacts the area of material to be cut. Use the key provided in the hand set
MS76. Use light pressure and remove only the minimum material necessary.