50 Nm
23--- 131
Cylinder Head
3---4
I. Fitting cylinder head
1. Measure the length of the cylinder head bolts. Compare
with dimensions shown in figure below. Change too long
bolts.
max. 142
max. 188,5
23--- 11
2. Screw the cylinder head stud bolts in to the cylinder block
to a torque of
30 Nm
. Fit the valve tappets if removed.
3. Check that the sealing surfaces are clean and fit the cylinder
head gasket(s) and the cylinder head(s). Ensure that on the
six cylinder engines both cylinder heads are parallel by
fastening lightly the exhaust manifold before tightening the
cylinder head bolts (the exhaust manifold can damage, if the
heads are not parallel). Clean and lubricate and fit the bolts.
420
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
320, 620, 634
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23--- 13
23--- 12
4. Pictures above show the correct tightening order of the cyl-
inder head bolts. The order has also been marked on the cyl-
inder heads.
5. Tighten the cylinder head bolts progressively as follows:
1. First tightening to
80 Nm
2. Tightening of
90
˚
3. Tightening again of
90
˚
.
6. Adjust the valve clearances (see instruction
4 C
).
7. Run the engine with a light load to the normal running tem-
perature (~ 75
˚
C).
8. Tighten the bolts
60
˚
and adjust the valve clearances.
Note!
After this the cylinder head does not need retightening.
Tighten the exhaust manifold bolts/nuts to
50 Nm
.
DO NOT OVERTIGHT!
