Cylinder head tightening

CYLINDER HEAD TIGHTENING

Diagram showing order for tightening bolts fixing cylinder head to crankcase

The correct procedure for tightening the cylinder head bolts is as follows, bearing in mind that for each tightening stage described, the order is that shown in the diagram at the side:

• lubricate the bolts and washer and leave them to drain for at least 30 minutes.

2 + 2 daNm

Pre-tightening, with torque wrench, in two stages (2 + 2 daNm), of cylinder head fixing bolts

• tighten the bolts to a torque of 2 daNm;
• tighten to a torque of 4 daNm using a torque wrench.

90° + 90°

Angular tightening, in two stages (90° + 90°), of cylinder head fixing bolts

• using an ordinary spanner, further tighten the bolts through an angular rotation of 180° in two distinct stages (90° + 90°) following the order given for each of them.

NOTE Where ASTADUR type gaskets are fitted it is no longer necessary to tighten the cylinder head fixing bolts after the first 1000 - 1500 km.