I'm planning on getting my heads cleaned and resurfaced. Whats the maximum I can shave off to increase compression. How much would you all recommend to get taken off. Also, what else besides replacing gaskets should I do while the heads are off. Thanks in advance.

 

Im not sure on the specs for decking, but while the heads are off I would look at the valves and valve seals. I would also do the timing belt if it hasnt already been done. And, I would chack the intake for dirt and whatnot and clean it out pretty good since its off.

Then again, higher compression isnt always better. there was a post I remember readin a lil bit ago (I cant remember if it was in the stickies or not) But it was talkin about compression ratios and whatnot. But if you decide to go that route then I would also look into a port and polish job and maybe a three angle valve job (if it is allowed without hurting anything of course). just my 2 cents

 

Are u saying that I shouldn't shave the heads? Thats the easiest way I see to increase compression without buying new pistons.

 

Either get your hands on a Nissan FSM or contact someone that really knows what they are doing.

Might want to read about porting the VG30 heads on Z31.com or similar site

 

milling the heads on these cars causes problems with cam timing as well..
if you're talking just a few thousandths, then it's no big deal.. bu if you remove enough to actually make a difference in the compression, then you're going to cause issues with cam timing.