mk1-forum.net

Hi could the clever among you advise on piston cc needed . Block is 1275 + 40 bore . Want to use a race head that has 16.4 cc . So what cc do I need in the pistons for approx 10.1 compression ratio

Now that is "techinical talk!"

from my rough calcs assuming a 40 thou deck height and a 3.4cc gasket you will need 12cc dished pistons.

There’s a compression ratio calculator that will give you an approximate number here. It might be tricky to correct the compression ratio with such small combustion chambers

https://www.classicminidiy.com/technical/compression

If you are using a wild cam to go with the race head you will need to work out the dynamic CR in which case your static CR would be able to be higher.
It`s way above my head but hopefully someone like Spider will be along soon.
You can have a little material machined from the piston crowns as well if needed.

That ratio calculator is great . Will probably go for omega 10cc pistons … thanks for reply’s … Shirley

Depends on the cam you want to use