Going from a 0.040" thickness head gasket to a 0.054" thickness head gasket will increase the combustion chamber size by about 2.745cc. Is that correct?

This is on a 3.903" bore.

Formula for volume of a cylinder is: pi(r)^2(h)

So r = 1.9515"
h = 0.054" - 0.040" = 0.014"

So we have pi(1.9515")^2 * (0.014") = 0.1675 ci

Conversion to cc

1L = 61.02 ci

So 0.1675ci = 2.745cc?

 

well, you did the math right, but you need to figure out the diameter of the gasket, not the cylinder bore. The gasket bore diameter is probably closer to 3.940 or so.

 

I had a feeling that was the case. Using 3.940, I come up with ~2.80cc volume reduction.

Taking it a step further and accounting for 0.030" milling.

On paper, milling 0.030" reduces combustion chamber size by ~5.88cc.

It then follows that a 66cc head with milling 0.030" and installing it with a 0.040" gasket brings the combustion chamber down to ~57.32cc. (8.68cc reduction)