Engine Overhaul Manual v8 40 46 | Valve Seat & Seat Inserts Refacing
ENGINE
OVERHAUL
11
Valve seat inserts - renew
NOTE: Service valve seat inserts are
available 0.025 mm (0.001 in) oversize on
outside diameter to ensure interference fit.
1. Remove worn valve seats.
CAUTION: Take care not to damage
counterbore in cylinder head.
2. Heat cylinder head evenly to approximately
120
°
C (250
°
F).
WARNING: Handle hot cylinder head with
care.
3. Using a suitable mandrel, press new insert fully
into counterbore.
4. Allow cylinder head to air cool.
Valve seats and seat inserts - refacing
CAUTION: Renew worn valve guides and
seat inserts before lapping valves to their
seats.
1. Check condition of valve seats and valves that
are to be re-used.
2. Remove carbon from valve seats.
3. Reface valves as necessary. If a valve has to
be ground to a knife-edge to obtain a true seat,
fit a new valve.
Valve seating face angle A = 45
°