Volvo D20 - Page 50

Group 27 Reconditioning engine
Cylinder head, c/eaning - inspection
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Clean inside of valve guide
Use rea mer 5224.
Note! Cutting oil must be used when reaming.
FB
Valves and seats must be ground-in af ter valve guide
replacement.
Grinding -in va/ves and seats
Operations F9-12
Machine grind intake valves
F9
Edge of intake valve must not be less than 0.5 mm
(0.02 in).
Important! Exhaust valves are stellite coated and
must not be ground by machine. Grind-in valve on
seat with grinding paste.
Mill or grind valve seats
Grind to 45°.
Contact surface (a) must be:
- 2.0 mm (O.OB in) for intake valve
- 2.4 mm (O.OS in) for exhaust valve .
F10
If contact surface is too wide reduce area with a 15
Q
cutter.
Importanti Outer diameter of cutter must not exceed
35.2 mm (1.39 in) for intake valve seats and 33.2 mm
(1.31 in) for exhaust valve seats.
F11
Measure gap between valve disc and cylinder
head surface
Gap = max 1.5 mm (0.06 in).
Replace seat and passibly valve if gap is too large.
Note! Two valve types are available, see G3.