Okay my f20 is sleeved with 87mm JE pistons w/ 5.5 Dome. the compression ratio right now it 11.34:1. I plan on using a 3mm head gasket which will drop it down to 9.12:1

first thing i was curious about is how much boost can a 3mm head gasket take??

Second thing I was wanting to know, Is the piston rings were filed to JE ring gap specs for high performance N/A. will their be enough room for the rings to grow under high boost??

my top compression ring is .0045"
second compression ring is .0050"
oil rings are .015"

I plan on at least making 450-500 hp

thanks for the input

 

quite a combination you have there.


the pro's will have to chime in on this one

 

BUMP

 

why didnt you just use low CP pistons?

 

Ive seen over 20lbs of boost on a 3mm headgasket, so thats pretty good for a big fix as far as compression goes and as for your piston question idk gl!

 

I dont see why the sleeve/pistons/and hg combo WOULDNT work . People have ran a Lot more than 20psi on 3mm head gaskets, as a matter of fact my turbo came off a 3mm hg car that ran 33-34 lbs on the dyno. As long as the thing is put together solid with no mistakes and its tuned properly you should be fine and have no problem meeting your goal. The potential is definitely there :thumb:

 

Isnt 33-34lbs of boost called abusing a 3mm hg! imo

 

I think that was Rob.. That was a race fuel tune.. 700+whp

The 3mm HG has been proven to put huge numbers out. How long it last is another question.. It would be fine to go etleast 18 psi on pump gas.. Thats just an opinion though. Many people will say to not even bother with the gasket and some will say how they used it with great success. Its a very controversial topic. I would say with some good fuel or meth u could easily push it to 25psi+.. Sorry I can not help with the piston right question you have.