Hi,

I know that the 4wd pistons in a 2wd motor will give you lower compression (7.8:1 i think).

I've got a 2wd motor that supposedly has 4wd pistons in it, although one of the pistons has copped a flogging from a valve, so ive bought a set of 2wd pistons to replace them.. although looking at the pistons i cant tell the difference between the supposed 4wd ones and the 2wd ones??

the '4wd' ones are still in the block. Is there an obvious difference between the two pistons ?

How do i tell the difference between them ?

If they are the same (both 2wd) i could get away with just replacing one piston.

I quickly measured the distance between the crown and the middle of the piston on both sets and i came out with 8.3mm depth for both (if i remember correctly )

I will try to get out there tomorrow and do a better measuring job.

Any help would be appreciated.
Thanks,
Damion.