Compression Ratios

i have 14:1 pistons for a 2ZZ engine, what i would like to know is what compression ratio i can achieve by increase the head gasket from original 0.8mm to 1.2mm?

Using nominal values, approximately 13.26:1.

That said, until you actually measure the engine and CC it, that could be different from the actual values. Manufacturing tolerances, whether the head and/or block were skimmed, whether the valve seats have been machined, etc, will all affect the true values.

Hi. My calculations show that it's going to be 0.5 (ish) reduction by getting 0.4mm thicker gasket. So does another site talking about cosworth head gaskets...

https://www.newcelica.org/threads/2zz-engine-technical-specifications-question.384898/

I made that calculator for Evo engines but it works on every engine providing that we know all variables...

Yes, the problem is the variables, as I said, and my figure was calculated from the adding the increased unswept volume to that which was calculated from the stock engine's swept volume and the cited nominal CR for those pistons, to give a corrected nominal value.

I would disregard the Cossie' examples because their much lower CR means much less proportional difference.

Again, until the OP actually measures it all up, at best we can just make informed guesses.