Manual - Chapter 1 Engine
31. Reassembling the engine unit: refitting the cylinder head
- Check that the sealing faces of the cylinder head and block
are completely clean and free from dirt, oil, grease, corrosion or
old gasket material, also that they are undamaged.
- Check that the tapped holes for the head retaining bolts are
clean right to the bottom and free from oil. A quick squirt of
aerosol-applied contact cleaner will clear any oil from each hole.
Carefully clean the bolts, particularly the threads.
- Fit the two locating dowels to their recesses in the cylinder
block and fit the new gasket over them. No jointing compound should
be used but a smear of grease will help the gasket to settle and
will hold it in place. Note that the gasket will fit correctly only
one way; check that all coolant passages, bolt holes, oilways and
oil drain passages are clear. Lightly oil the threads and under the
heads of the cylinder head bolts and check that all are fitted with
their flat washers.
- Refit the cylinder head, positioning it over the locating
dowels, and fit the retaining bolts. Tighten them lightly at first, until all are
in place and the head is settled.
- Working in the sequence shown in the appropriate accompanying
illustration tighten the bolts evenly, in gradual stages, to the 1st
stage torque wrench settings specified; this seats the gasket.
- After a 20-minute wait, repeat this procedure but tighten the bolts to
the higher 2nd stage torque wrench setting specified. As can be seen
from the accompanying photograph, the bolts can be tightened (but not
all can be removed and refitted) with the camshaft in place; therefore
this second stage tightening need not hold up reassembly work.
- Where appropriate, refit the engine front left-hand mounting bolt and
nut; do not forget to refit any shims that were found on removal.
Fig. 1.10 Cylinder head bolt tightening sequence - 75 models
A to H - head bolt tightening sequence *
1 to 8 - camshaft cap location numbering
* reverse for slackening
Fig. 1.11 Cylinder head bolt tightening sequence - 100 models
A to J - head bolt tightening sequence *
1 to 9 - camshaft cap location numbering
* reverse for slackening
31.3a Fit new gasket over two locating dowels (arrowed)
31.3b Clean threaded holes and oil retaining bolts lightly as described before refitting
31.5 Tighten cylinder head retaining bolts evenly to first stage torque setting...
31.6 ...then to second stage setting after specified waiting time - note tool used to tighten bolts with camshafts in place