Hey chaps
Need a little help regarding head gasket thickness.got block decked and head skimmed for fitting wrc gasket but have noticed my 7.2cr cosworth racing pistons (with valve cutouts)are protruding 1 mm above the block.my head is 138.45mm thick.was trying to run a wrc gasket for safety but do I need to change to a thicker one??any help would be greatly appreciated as I'm really Stuck.thanks eoin

 

If the pistons are that far out of the hole, either the block has been machined too far, the rods are too long or the pistons are wrong.

Generally speaking you want around 1mm between the head and top of the piston to ensure the piston never makes contact with the head.

7.2:1 is insanely low too.

 

The factory protrusion was actually 0.5mm on these when new.

You still have aproblem, you can get 1.3mm multi layer gaskets, but I cannot see how you can have a 1.0mm protrustion and a comp ratio of 7.2:1 unless your pistons are like buckets !!