I'm using a Flat-Out big bore 4g63 gasket on my 4g64, but Cosworth is good too.

 

both my car and my buddys 2.4's are running cometic HG's with no problem. im only at 32psi, but hes at 50ish psi and it holds just fine

 

How it seals is determined by machine surfaces and in general bore size etc.

A stock bore is gonna have a better chance non o-ringed then a 87mm .020 overbore

My customer 5leeperisah purchased a custom Cometic HG in 2011 and it did not look custom at all.

I purchased another one to compare since my cost is so low, like $62 dealer cost, and it was identical. We overlayed it, we took a digital caliper to every inch of it and it checked out identical.

It also came sealed in the factory packaging. So i really don't know whats custom about it.

Maybe at one time or another they were custom due to the thickness not being available to the public, but that's not the case any longer for the past 3 years.

The part # for the gasket used to be H1528SP6051S

now it is superseded by part # C4591-051

All that said, I use the cosworth FSL 87mm 1.3mm in my car and no issues. But my heads O-ringed. I also only did 32psi which is around 740-770 in my specific application.

Now comparing the Cosworth to the Cometic they are pretty similar.

Its hard to say what will do what. The Cometic seems well made. I think with Orings it wont leak either just like the Cosworth but for way less $. It does seem like the Cosworth has something different done to the fire ring on the gasket though when comparing side by side.

Heres a article where cosworth claims otherwise though, and yes the competitor is Cometic in that comparison.

http://www.motoiq.com/MagazineArticl...-Released.aspx

It should also be noted, if you don't have at least 1000 miles + on your car then you cant claim your gasket is worthy.

They don't start to show signs of failure until around 1000~ miles non o-ringed.

 

Felpro permatorque is the way to go cometics blow with low boost I currently have a felpro on my 3g running 10.5:1 and 35psi

 

I had a Power Enterprises and another one before (Name escapes me). Running OEM modified AMS HG now.

 

How much boost the turbo is making is virtually meaningless as a measure of gasket durability. That's a bit like saying, "I can rev my engine to 9k rpm, and it doesn't break," with no other information given.

 

Bringing back from the dead.

After looking at a couple options, I found Buschur is now able to get the OEM gaskets bored out to the proper 2.4 size. So thats where I got a couple. Thanks David and Nick!

Felpro did offer to make one but they want $10k for so many gaskets and it comes out to like $300 per gasket. Unfortunately I'm not rich so that was off my plate. Maybe a company that specializes in Evo's can do that one day and stock the Felpro option.

I also had in my hands a JE Proseal but it was also a 3 layer like Cometic and honestly, I didn't want to be the guinea pig for these gaskets.

 

The Cosworth gaskets work well...

 

I think those are still a 3 layer and after researching those, I wasn't that impressed with Cosworth like some of the comments from Buschur in this thread:

https://www.evolutionm.net/forums/ev...ver-40psi.html

About the same price as the modified OEM 5 layer head gasket.

 

Felpro does make a 2.4 gasket but its the thinner version so you need to worry about piston to valve contact and its not a 5 layer like the OEM. I was talking about the thicker 5 layer Felpro HG most DSM guys swear by that Felpro will custom make if they get an order for $10,000.

 

I was running the JE proseal with no issues until I hit 40psi. Then I realized I only torqued my l19s to 95ft/lbs. It started to seep coolant into cyl 3. A retorque to 105 stopped the leak. Im switching to a cosworth and o-ringing the head. Mainly because cosworth has nice receiving grooves for some o-rings.

 

Good to know.

 

I cant find a 87mm hg from hks

 

Honestly, I don't know if they even make one. It was suggested by Magnus. But now you can buy a Mits OEM gaskets in the 87mm bore size cheaper so why bother looking at HKS?

 

Rodent,

Which gasket did you end up going with? Were you having trouble with a certain gasket before making this thread?



To everyone that recommended Cosworth, which one did you go with, 1.3 or 1.5mm thickness?