Not just the gasket or if you O-ring it. There is more to it than that. 52psi on a 2.4 is doable when the formula is there.

 

Great info.



I remember scuttlebutt about different casting quality between a Mitsubishi block vs a Hyundai or Kia sourced block and whether or not the cranks (or blocks) were nitrided (perhaps Mitsubishi Evo 4G63 only). But I guess that was all inconsequential in a well built engine or not true.

 

Now, I have a question. I'm in the process of building a 4g64 with a g4js head. All of this talk about head gaskets and such is making me wonder, why not use an oem 4g64 head gasket? Assuming that they are the same material and thickness as one another, so why not? IIRC, the oem 4g63 head gasket can hold up to quite a bit of power, comparing them to cometic, cosworth, power enterprise, etc, etc.

 

I think it's because if you use the OEM 4g64 head gasket it wouldn't line properly with the 4g63 head therefore causing malfunctions and whatnot... You would need a modified 4g63 head gasket I think. I'm not sure though it's what I understood from previous threads and discussions.

I'm not a professional or anything of that sort, just an enthusiast :P

 

Ya compression and strengthening the block would be important also for high power.

One of your local customers running a 2.4LR that had a hg issue told Steve (isah5leeper on here) you guys O-ringed him to resolve the issue. It was in response to the thread Steve made asking the community if he should oring or not before he puts on the t3 6466 kit.

It seems to me most people running a lot of boost and power on a 4g64 block are all oringed. (not all but a lot) I oringed my head because it was oringed before on my 4g63 block, so i just had Buschur's machine shop re-oring my new head like the old one was.

I'm a firm believer in Orings. I know some people are fully against them though. But since i had them in my old setup and no issues, there's no reason to not reuse what has worked before.

 

The composite 4g64 headgaskets are only good for up to 86mm I believe. Most people with 2.4's are running them atleast .020 over because that's what they require usually to fully clean up at. So that makes them 87mm.

I never researched into a 4g64 headgasket, until just now quick, but it looks like the stock 4g64 HG is composite and not MLS and can not handle boost well at all.

 

I also know personally 4-5 people on this forum with 4g64 blocks running O-rings with no problems "all making over 650whp." 2 of them ran non o-ringed heads before and nothing but problems. Don't want start a argument over this but I choose to get a o-ringed head when doing my T3 6466 build.

 

I used a stock HG from a late model 4G64. It is a 2 layer metal gasket. I have no issues. It will raise compression compared to a thicker gasket. I don't know if more or less layers helps sealing better but mine was good at approx 565whp. I hope to push it so much harder once my clutch can handle more power

 

so whats considered high boost for the 2.4? I plan on seeing 32-34 most.

 

Id say that is high boost. 32-34psi if you are holding that to redline.

anything over 30psi to redline would be high boost to me.

Id like to try to run near 40psi when Im at the drag strip with my new setup if i can get used to the power.

 

Hey tom not to tred to far off topic but I'm about to start a 2.4lr build and thought that O-ringing would be a good idea and on paper it seems to be. But what are the reasons that have others completely against it? Sorry again for a somewhat off topic question.

 

It's on topic enough for me! All this info is great- the more, the better! I really appreciate everyone's input- thanks guys!

 

I did it on mine. I never had an issue with O-rings, so ill keep using them until i have an issue that proves otherwise.

Those that who are against them, are against them for using them in the wrong way. Not necessarily against O-ringing in general.

I never had an issue with mine, so until I experience an issue with my personal car, then ill continue to use what has been working for me.

I have no problem alerting the community when/if I have any issues with my car. I share everything if I feel it will help someone else out. As do many other vendors on here. That's what makes the evo community so open and resourceful.

Technically speaking, when the head and block surface are perfectly flat, an MLS gasket should be all that's necessary to fully seal the HG.

 

Thanks Tom. I'll continue to plan to do O-ringing then, since I would like to be able to run 37-40psi..just seems like a good bet to me