Manual - Chapter 1 Engine

31. Reassembling the engine unit: refitting the cylinder head

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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