I am working on a 2004 Evo 8 and Mods are as listed.

-Built 2.4 4G64 bored over .020" 9.0:1
-4G63 head with oversize valves crower valvetrain and BR 272 cams
-L19 ARP headstuds

I cannot get this thing to hold over 30 psi with the cometic 4G64 head gasket, Power Enterprises makes a 4G64 overbore gasket for this setup. Has anyone used this gasket before, I am looking to push 40psi on race gas.

Also the head has been milled .015". Is the head still ok to use?

Please anyone who has any experience with the 4G64 please chime in, any help or constructive thoughts are greatly appreciated.

 

ive heard stories of 4g64 head gasket issues....as long as the head studs arent coming loose...i would say try the power enterprises gasket....but be careful how much they take off the deck of the head because if they take too much off it will have an effect on ur compression ratio....and u also need to make sure the surface of the block where the head bolts on to is even and also clean so u make a good tight seal....gl

 

Ive heard that once the head gets thinner than 5.180" deck to valve cover surface it is time to replace. Im not worried too much on the comp ratio .015" is not going to change it enough to matter on my setup

 

BUMP does anyone run a 2.4?

 

I have had several issues with the Cometic head gaskets holding up on a 2.4L build. The tune could have been a factor as well but in the end, we ended up doing a 2.3 to get rid of that block. Good luck.

Aaron

 

I'm just finishing up my 87mm 4G64 build right now with a PE head gasket, so I don't have any real info for you yet. I have heard very good things about the PE hg though, and that is why I chose it. Supposedly it is very similar to the HKS, just .5mm bigger bore. FWIW, Norris designs runs 1k+ hp through a 4g64 with an HKS gasket, so we know it can work.

edit: And btw, I've never heard of anyone having good luck with a Cometic on a 4G64 block.

 

One more question, what did you torque your L19's to? Mine are at 100ft/lbs.

 

For some reason, that sounds a little high. What is the manufacturers recommended torque?

 

Thats what ARP old me to torque them to, but I never found it in writing. I just called and thats what they told me. Keep in mind they are L19's.

 

They told me 110-119

 

Cometic Gasket is the problem. I had several blow coolant and around 25-30psi and in the 500-600whp range. I would have had the PE gasket but the 6bolt version that I need is unobtainable so I ended up with a FelPro gasket. Good luck and throw that cometic in the garbage.

 

Now I'm wondering if I should up mine. I really don't want to f with the head gasket.

 

Did you o-ring the head and if you did who did it and how much??? The problem that im finding is that no one wants to o-ring a 4G63 head for a 4G64 let me know.

 

No I did not o-ring the head. I was told it was not necessary with a good hg. John Bradley is building a 4g63/4g64 combo using the PE hg and he is not o-ringing it either. The shop that built my head would have done it though. Millenium Motorsports in Temecula, CA.