When I did the Sarah Project motor, the Project 15A motor, and the Misty Blue motor, I got into tight squish by decking the engine block to have the piston crowns come up above the deck either 10 thou, or 12 thou, or 18 thou...to get the squish clearance I wanted for each of those motors.

At that time, that was the way I had to do it, if I wanted to use a stock type head gasket that is 0.047in thick when compressed.

Up until a year ago, the only alternative was to have a copper head gasket made out of copper sheet thinner than 47 thou. Copper head gaskets work, but they are a bit finicky when it comes to sealing, and staying sealed. Finicky head gaskets are not something that I would strap a customer with.

Last year, I assisted in the program to get Cometic to develop and make MLS [multi layer steel] head gaskets for the Volvo SOHC redblocks.

Besides their superior strength, the MLS HGs can be made in different thicknesses.

So....instead of having to have the block decked to achieve a certain piston positive deck height. it is now possible to measure the piston deck height, and order the correct thickness Cometic MLS HG to get the squish clearance desired.

For this B23, with a piston deck height that is negative 8 thou, I could use one of two thickness Cometic MLS HGs:

...a 27 thou thick HG to get 35 thou squish,

...or a 30 thou thick HG to get 38 thou squish.

This pic shows a 30 thou HG in place for a test fit...

...and just to see how beautiful it is sitting there.


how sweet it is.