Rolls-Royce 20/25 - fit cylinder head



dowels & studs


Centre, the 5 studs that fit between the cylinders.  Either side are the two hollow dowels that screw into either end of the block face.

dowels fitted


Centre studs and hollow dowels in place.

The head gasket should be fitted using grease not joint sealant.  The easiest way to apply the grease is to apply directly onto the faces of the block and head rather than juggle with the gasket.

head fitted


Cylinder head in place.  The nuts should be tightened from the centre, working outwards, in a criss-cross pattern.   Several tightening cycles will be needed, taking down the nuts by small steps.

Preliminary tightening was done by 'feel' and then checked using an inch/lb torque wrench.  First pass readings were in the 216-240 "/lbs (18-20 ft/lbs) range.

Modern gaskets seem to need at least 4 tightening cycles.  The engine will be left to stand overnight before rechecking.

Under no circumstances should the head studs be taken above 20 ft/lbs; the elastic limit on these very long studs is roughly 24 ft/lbs.