I'm wondering how many have this combo, a block which had to be bored .060 and then using a stock mitsu headgasket.. please let me know your setup and if there were any problems, and what kind of whp you are/were running

 

.060 over? Thats crazy

 

^I agree, I wouldn't want to mess with anything more than .020 over on a boosted block and the HG would have to fit that bore.

 

86.5mm (.060 over) will need to use the Cometic 4G64 gasket.

 

Yea the whole thing kinda came from a bad situation.. just trying to get the car back on the road at the time, and I bought a used block of a member on here... long story short one cylinder had a bad spot that needed to be taken out, and going from a .040 to a .060 smoothed it out.. looking back I'd never do that again, but I also had 700 bucks into the used block and crank


Alright, sounds like you have had some experience with this perhaps.. the issue I've been fighting is basically as soon as I start building over 35psi or so (fp black, 2.0 E85) I have some sort of issue that seems like a headgasket.. either a freeze plug comes out, or the coolant bottle pressurizes. I've taken the head to a machine shop and had it pressure tested, it holds good and is pretty flat, if I recall its .002 I think. Block measures good too, .0015
Replaced with new arp's and gasket.. same issue as soon as you push it.

 

I am running a 86.5mm 4G64 block and am using this gasket right now. I'd like to think it works and since there isnt any other difference between the two, I think you'll find similar results. Torque to 95 ft lbs on L19s. Block and head prep are critical, so sand with a machinist's block and 1200 wet/dry withand WD40 until its smooth as a baby's behind.

 

Thanks again John, one more question, what do you use on .040 4g63 blocks for a headgasket?

 

Cometic 86mm bore.

 

alright I f'd up this one.. had taken a break from the Evo for a few months and forgot wtf I had in the block. It's .040 over with stock HG, no o-ring to the head or block.

I think I'll see if a mod can either help me change the thread name or delete it, unless the .060 over info is good for other people searching in the future.

In the meantime, can anyone tell me if they have had any negative experiences with .040 over and the stock headgasket?

I see John does not use this combo, but can anyone tell me if it works for them in over 550whp setups (looking for high cylinder pressure) or did NOT work?