A15 trubo project on the go. brought the engine in need of new pistons.
as i plan to turbo charge the engine, will the tx3 turbo pistons or mazda dohc turbo equivlent fit straight in? and what comp ratio will they give me?

what about E15 turbo pistons as well out of the FWD langleys and ET pulsars?

come on some one must be able to help me out here, please.

This is one of those "gray areas", talked about somewhat, but no real definitive answer. Try the search box on the left side. Look for

A15 piston%

For example, EFI - Turboing A Series has a discussion of puttin E15 pistons in the A block.

The Sports Car Club of America GT5-class racers seem to know a lot about the E15 parts interchange, apparently they use the E15 head on A14s. Search the Web for GT5 E15 A14 and you might find more info.

by the looks of that thread they will fit in, if i use the E15 conrods, and will give me the cmop ratio i need because of the deeper dish in the piston crown. is that right?
someone please help me out, i need to get this done.

you might have to get hold of a piston specs catalog and check it out yourself. Things you need to look for are:
*diametre of piston
*gudgeon pin dia
*piston compression height (height of piston from pin to crown).

rods length will affect your deck height as well, so you need to find out the E seires rod length

To calculate the effect it will have on your CR, you need to work out the volume of the cylinder at BDC and divide that by the volume of the cylinder at TDC.

V(bdc)=swept vol + piston vol + head gasket vol + combustion chamber vol

V(tdc) = piston vol + head gasket vol + combustion chamber vol

for head gasket volume, work on a crushed gasket thickness of .040" (1mm)

the piston volume can be a positive (dished) or negative (dome) value. if the E15 pistons are dished you can calculate the vol in the same manner as the combustion chamber. typically the piston volume includes the deck height volume as well. If piston is above or below deck height at tdc, measure that and calculate that vol as well.

it was in the link that the gudgeon pins are the same size and everything, so they should bolt straight in right? what kind of PSI could i run with the standard conrods though? if i add a decompression plate i will get about a 7.2:1 CR.