Cylinder Head Gasket Replacement? ?

[Chris KC]

Chris KC, I read your input with interest (I do not doubt your figures on expansion etc.)but you make no reference to the expansion on the steel head studs. Surely these increase in length when hot thus require re tightening to bring everything to the correct tightness. When cold they maybe slightly overtight with contraction but that is a small price to pay to have them correct when running.

John Mason

They do expand John, and it wouldn't be a problem if everything expanded the same amount. But a cast iron head expands less, and an alloy head more, than the steel studs do.

If the torque applied at cold condition is correct the change in clamping force at hot condition will be accommodated.