Sisu Diesel 645 Series Workshop Manual page 34

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
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 cylin-
der head gaskets and the cylinder heads. Ensure that 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.
Tighten the exhaust manifold nuts to 50 Nm. DO NOT OVER TIGHTEN THE NUTS!
Cylinder Head
14
16
12
4. Picture above show the correct tightening order of the cylin-
der head bolts. The order has also been marked on the cylin-
der heads.
5. Tighten the cylinder head bolts progressively as follows:
43--- 10
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.
10 7 5
3 1
4
2
8 6
50 Nm
3---4
9 15
17
13
11
43--- 11
43--- 12