has anyone tried this?d15b7 block, zc pistons, d16y8 head +gasket. i heard its like 11.4:1 compression. im puttin it in my 91 si hatch

 

ttt

 

ttt

 

d15b7.... That is the 88-91 Dx block right? If it is, it should be able to work. The Dx block is different than the A6 block - BUT they both the Dx head and the A6 head are pretty much the same (except the cam, and prolly some other misc valvtrain parts.) the head itself is the same. SO, since the Dx block has the same mating surface between the head and the block, it should be able to accept all of the same heads that the A6 block can accept.

Now, from what I know zc pistons with a Y8 head combo is asking for trouble... Zc pistons raise the compression ratio by one whole point over A6 pistons.. A Y8 head with A6 pistons underneath it would yeild either a 11:1 comp or a little bit lower (approx). Which would mean that a Y8 head combined with zc pistons would put you up to the 12's... Your risking the top of the piston smashing into the bottom of the head.

In addition to that, the d15b7 has a different crank than the d16a6... Which means that the stroke is different. This might affect compression numbers as well? I dunno.

If I were you, I'd stay away from the ZC pistons. A6 pistons give a nice high compression when combined with a Y8 head.

 

d15b7=95 dx block