Maxima V6-2960cc 3.0L SOHC MFI (VG30E) (1990)
Valve Seat: Service and Repair
REPLACING VALVE SEAT FOR SERVICE PARTS
1. Bore out old seat until it collapses. The machine depth stop should be set so that boring cannot continue beyond the bottom face of the seat recess
in cylinder head.
2. Ream cylinder head recess.
Reaming bore for service valve seat
Oversize [0.5 mm (0.020 in)]:
Intake
44.500 - 44.516 mm (1.7520 - 1.7526 in)
Exhaust
37.500 - 37.516 mm (1.4764 - 1.4770 in)
Reaming should be done in concentric circles to the, valve guide center so that valve seat will have the correct fit.
3. Heat cylinder head to 150 to 160°C (302 to 320°F).
4. Press fit valve seat until it seats on the bottom.
5. Cut or grind valve seat using suitable tool.
6. After cutting, lap valve seat with abrasive compound.
7. Check valve seating condition.