singleslamman

hello, Im new to the forum and was wondering about 78mm pistons. considering that they are custom made since they are so large, if you purchase 78mm z6 pistons, will they still work for y8's? I know all d-series 75mm pistons are interchangeable, just wondering about the large custom made applicaqtions. Any info. woul dbe much appreciated, thanks

blk92_d16

What you would need to have done to your block is it would need aftermarket sleeves, like Dartons, Golden Eagles, etc etc. Then you'll have to have it bored out to the mic'd piston diameter. Not to the best thing to do unless you've got thousands to spend!

singleslamman

lol sorry should have mentioned i already have the y8 block sleeved by darton, and bored, just trying to figure out if lilcivic04's z6 78mm pistons will fit my y8 but yes the whole process is very expensive indeed!

big-cat

they should, I do not see whey not the bore is 78mm....................(boost or n/a?) what compression are the pistons suppose to put you at?

singleslamman

they are low comp. should put me at 9:1, building for turbo of course. The only thing that trips me up is when you order these, they dont list their pistons as just "d16" they go model specific, such as z6 and y8.

big-cat

yeah but pistons for any d16 or d15 should be the same, its the bore that matters, they will work I do think that they mean it will be 9:1 with that head(y8 or z6) so you might want to double take on the head and valves and head gasket to get the exact compression ratio that you want.

singleslamman

ty, yeah that was my other thought, that maybe they were referring to the piston to deck height possibly, and if tat were the other factor i do believe it would only be a small increase maybe to 9:4 or something like that but ill have to look into that.