Hi all,
I am trying to figure out how to increase the compression ratio on an A15. The dish in the piston of the engine I have is quite deep, yet the combustion chamber is small.
Does anyone know if the A14 pistons will go in the A15?
I know the A14 has the same bore, but do the A14 pistons have a smaller dish?
And is the wrist pin to deck height the same for both engines?
Any technical info is appreciated!
Thanks.

The A14 and A 15 from memory have different pin heights.

I used UC mazda pistons and machined them flat and ended up with 12.9:1. This may be alittle more than you were after though.

Dattoman, I've never heard of UC Mazda pistons. What are they?
Can I still use A14 pistons, and mill the block down to match?

I run A14 pistons in an A15, Its a very simple swap, however, you have to "eye-brow" your pistons for valve clearance. This (of memory) gives to 11.5:1 compression? (no milling of block needed) - Hope your racing this car, without running 100oct Racing fuel (avgas) it will only last you about two hours before it pre-ignites itself to death.
Send me a reply if you want some more info and I try to dig up exactly what I did to my motor.
Micko