48
2677
2267
2677
Note the oil holes!
Face-grinding cylinder head
If leakage is discovered or if there is a trace of a blown
head gasket, there is no reason to check for unevenness.
The head must be machined or renewed anyway.
A rough check can be made with the help of a straight-
steel edge. A slit of light between the straight edge and
cylinder head indicates that the cylinder head should be
machined.
Cylinder head unevenness must not exceed 0.01 mm
within a distance of 100 mm and 0.02 mm across the
entire width.
A more exact method must be used when checking cyl-
inder head unevenness since the tolerances are very
small.
Machining
It is most important that the contact face for the cylin-
der liners is even. Max. surface finish (roughness) is
0.006 mm.
The overall height of the cylinder head after machining
must be minimum 114.65 mm.
There is no need to alter the depth of the groove for the
cylinder head seal, providing machining stays within
permitted limits.
After machining, the distance A from valve disc top face to the
cylinder head face should be.
Min.
Inlet
0.05–0.5 mm
Exhaust
1.2–1.7 mm
If additional cylinder head machining is required, the valve
seats must be ground down to enable the valves to sink down.
