Valve Seat: Service and Repair

VALVE SEAT RECONDITIONING PROCEDURE





(1) Before correcting the valve seat, check for clearance between the valve guide and valve and, if necessary, replace the valve guide.
(2) Using the special tool or seat grinder, correct to obtain the specified seat width and angle.
(3) After correcting the valve seat, lap the Valve and valve seat using lapping compound. Then, check the valve stem projection.

VALVE SEAT REPLACEMENT PROCEDURE





(1) Cut the valve seat to be replaced from the inside to thin the wall thickness. Then, remove the valve seat.
(2) Rebore the valve seat hole in the cylinder head to a selected oversize valve seat diameter.

Intake valve seat ring hole:
0.3 O.S.: 34.30 - 34.33 mm (1.3504 - 1.3516 inches)
0.6 O.S.: 34.60 - 34.63 mm (1.3622 - 1.3634 inches)
Exhaust valve seat ring hole
0.3 O.S.: 31.80 - 31.83 mm (1.2520 - 1.2531 inches)
0.6 O.S.: 32.10 - 32.13 mm (1.2638 - 1.2650 inches)





(3) Before fitting the valve seat, either heat the cylinder head up to approximately 250°C (482°F) or cool the valve seat in liquid nitrogen, to prevent the cylinder head bore from galling.
(4) Using a valve seat cutter, correct the valve seat to the specified width and angle.