Topic: Non-F2 65mm Pistons in F2 Yield What Compression Ratio?

[IDontKnow]

I'm trying to decide on pistons for my rebuild and am considering using a non-F2 big bore kit in my F2 engine. 

I know the combustion chamber on the F2 heads is larger, the deck height is slightly higher, and that the OEM pistons have slightly larger domes to account for this. 

After the 3mm over-bore for the 65mm pistons, I presume the compression isn't going to be any lower than original with the extra 100cc's of swept volume.  Is this correct?  Does anyone know off hand what compression ratio is achieved in this scenario?  Thanks in advance to anyone able to share their thoughts.

[lucky]

The compression ratio will depend on the shape of the top of the new piston.

We would need a lot more facts.
If you are doing this job you need to check all of the clearances since they are aftermarket pistons.

Make sure to keep you old pistons for measurements.

[IDontKnow]

Found the answer to my question.  Thanks!

Soooooo, will these work in my '75 CB750F?

Yes. Get the head milled about 0.010" in the process, too, and the final compression comes out to about 9.4:1.