SprayinCX

i want to get my head shaved on my d16y8. i need to know how much to have it cut to raise it to like 10.5:1 or 11:.1. thanks

RyanEJ8

I would recommend domed pistons, over milling the head. Too many possiblities of side effects.

SprayinCX

please explain i'm a idoit

RyanEJ8

Milling the head gives bad valve to piston clearance issues, and shortens the distance between the cam gear and crank causing more slack on the timing belt. Can get messy.

RyanEJ8

There are "safe" limits to milling a head, but I think most people will agree with me that domed pistons are a better way to raise C/R.

Irishweird00

buy some z6 pistons, or some a1 pistons. The z6 would be around 11:5 i think, the a1's would be around 12:5:1 compression.. and the best part about it, they are cheap

SprayinCX

if i go with differ pistons is there the issue about valves clearance or anything else i would have to change?

RyanEJ8

With higher compression, there can always be valve clearance problems if you don't tune your timing properly, but it is a better place to start than with a milled head. I will be going to 10.5:1 SRP pistons with my nitrous setup. I might consider 11:1 if I can find someone that makes them for cheap. I know Arias makes them.

vladd

i always heard that z6 pistons will give around a 10.3-10.5 cr, and the a1 pistons around a 11.1 cr (in a d16y7/8 block).

Irishweird00

d16a1 pistons (stock bore) in the following with a y8/z6 metal head gasket (no mill):
d16a6= 11.08: 1 compression
d16z6= 12.03: 1 compression
d16y8= 12.61: 1 compression

z6 is lower, in the y8 in the 11's i know that

KENetics1

iTrader: (3)

Get some jdm zc pistons or 88-89 teg(d16a1) pistons. THey come domed from the factory and there not that expensive and raise your compression a pretty good amount too.