Valve Seat, Mill
Place cylinder head on two blocks of wood.
Insert Guide Drift KM-340-7 up to stop in valve guide and tension.
Place Valve Seat Cutter KM-340-11 with 45� face (note arrow on cutter) on valve seat.
Apply handle with intermediate piece and begin milling, removing as little material from valve seat as possible. Apply low pressure to cutter exactly vertically from above, so that seat lies concentrically to valve guide.
Then perform upper correction with 30� cutter. Use same cutter for exhaust and intake valve seat rings.
Note valve seat width (see illus. I)
1 = Intake
2 = Exhaust
| Engine | Cutter | Valve seat width (in mm) | |
|---|---|---|---|
| Intake | Exhaust | ||
| 1.2 ltr. | KM-340-11 | 1.3 to 1.5 | 1.6 to 1.8 |
| 1.4 ltr. | KM-340-11 | 1.3 to 1.5 | 1.6 to 1.8 |
Check contact pattern. Coat valve seat with touch up paste. Guide valve into valve guide and gently turn 1/4 turn exerting slight pressure. Lift valve and check contact pattern. If the valve does not contact completely, recut the seat again slightly.
Grind in valves - see corresponding operation.
The valve stem must not protrude from the cylinder head by more than the specified dimension "3" (see illus. II). Measure projection with KM-419. If dimension "3" is exceeded after remilling the valve seat or regrinding the valve (see illus. II), the valve seat is too deep and the cylinder head/valve must be replaced. The end of the valve stem must not be reground.