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View Full Version : best headgasket and head bolts



Sundance 6g72
06-15-2011, 05:13 PM
i know brent likes to use 1st gen dsm head bolts? im assuming thats for the 4g63 turbo. anything special have to be done when using these bolts? if i do some digging i can find how he toques them.

also, can we use stock dohc twin turbo headgaskets? they are mls and i think thats the route i should go for my boosted motor.

im getting rebuilt heads if anyone is wondering, so any suggestions on the head built up would be nice. its just going to be a mild built with stiffer valve springs and a better cam to get me to 7k rpms with megasquirt. but everything inbetween is still not known to me and im sure im missing something important.

bond_bbs
06-15-2011, 11:00 PM
Pretty sure brent used Cometic DOHC MLS head gaskets, but Felpro make a set of MLS head gaskets for cheaper. I know some people are all Cometic > Felpro, and I would generally agree, but the MLS Felpro's I put on my 3.0L were pretty good. Friend who ran a Stealth RT (24V N/A) with a 200shot of nitrous (395hp at the front wheels with just nitrous and a tune, factory everything else) swore by the MLS Felpros he had on it.

Edit: Found the Felpro MLS PermaTorque or w/e they're called for $39 each.
Click Here - Im a link! (http://www.importperformanceparts.net/imports/felpromls-chrysler.html)

---------- Post added at 11:00 PM ---------- Previous post was at 10:54 PM ----------

I think the part # - from what I found on TD is Felpro 9112PT. Both heads use the same gasket.

Sundance 6g72
06-16-2011, 01:19 PM
thanks for the link

Ondonti
06-18-2011, 07:41 AM
I used 95mm cometic MLS before but the oversize bore was for my oversize piston forged motor. Oversized gaskets are harder to seal.

The best combo is OEM TT MLS gasket + OEM stock headbolts (what you already have installed, assuming they are in good condition).

I use Felpro composite 12 valve style headgaskets right now. Cheaper and they have been specially redesigned to do a better job then what we have stock. They have a copper wire in the fire ring.
I would not try to save money and get a Felpro MLS over OEM mitsu MLS.

Since we have cheaper weaker pistons, I think the Felpro composite is a good idea, plus the copper wire is able to go back to shape if you lightly unseat it. This can give you more of a fuse headgasket instead of a timebomb. Even a stock paper headgasket can be enough to blow pistons when your ring gaps are really small and you detonate hard.

OEM mitsu MLS and headbolts are good for any power level. The composite Felpro I have used handled 14 pounds of boost on a 10:1 motor 67mm turbo. I don't think it was even breaking a sweat. If you knock, even small amounts of boost are a bad thing even with small turbo. Headgaskets are not a weakness for us. If the headgasket is not sealing, its just an indication of a serious problem. Back in the day when I had any problems, it was just an indicator of serious knock. I didn't care because I had no timing control. Yay Megasquirt. 12 degrees of base timing might be okay at 5 pounds of boost, but when you are over 20, its going to go boom boom even with race gas or E85 on stock pistons. 12 degrees of base timing actually gives us 38 degrees of total timing and thats WAY too much for 20psi. Turbo dohc guys on race gas and 25-30 pounds might only have mid 20 degrees on C16 race gas (116octane), and way less on pump. Thats how hard I was working stock components. Used reasonable timing plus good fueling and you can have longevity.

Sundance 6g72
06-18-2011, 02:38 PM
where can i order oem MLS TT headgaskets? im sure atuozone is just going to try and get me to get felpro mls regardless if i say its for a duster or a 3000gt.

the thing that gets me though is that we cant use DOHC heads because coolant passages are different? as in they dont line up with our block. this is what ive been led to believe so it would make me think that dohc TT headgaskets wont work for us...

Ondonti
06-18-2011, 10:55 PM
OEM mitsu = mitsu dealer. If you want to buy them online, buy them at "Cherry Hill" mitsubishi, which is actually in the NE USA, might even be in your state, I dont remember. THey give good deals and I think you can get a 3si.org discount if you know how.

We can't use dohc heads because the timing gear is very different (wider is the biggest problem) and even if that worked, you would need a custom tensioner setup because we don't have the same boss location to bolt that up. The headgaskets fit fine. There is one coolant passage that is sketchy, my cometic barely sealed that spot, but it was enough.

I would rather use the Felpro composite headgasket with stock pistons. With forged pistons, you detonate and you won't break a piston so easily. We don't have head sealing problems until you get really high in the HP area, above 400 on the dyno. If you avoid detonation, your heads will seal with much much higher hp.

I have tried all sorts of headgasket combos, including welding wire into used OEM dodge headgaskets, and adding copper wire to OEM MLS gaskets (diamante). The composite Felpro is specially redisigned, they even have an online PDF article about sealing our heads (in which the other technical data beyond the headgasket is all wrong) and how they designed a special headgasket for us, and its sorta a recent thing. Don't take the bad words 2.2/2.5 guys have for Felpro headgaskets to heart when it comes to other headgaskets. Even their MP gaskets fail with regularity. Most of it is caused by detonation on slow poorly tuned cars.
BTW they are cheap! They have a huge quality difference compared to our stock headgaskets. I put a coat of copper spray on them and when you take the heads back off, the headgasket comes off in perfect condition, leaving nothing on the head or the block! I think they will behave the same without any spray because they are different material then the OEM silver goo impregnated paper. Composite ftw. My Holset thread has pictures of a brand new composite gasket.

bond_bbs
06-19-2011, 01:36 AM
Funny you say that, as I had mentioned to Sundance6g72 on TD that a friend of mine had an N/A DOHC Stealth, and he swore by his Felpro head gaskets, even pushing a 200 shot through the factory motor. All he did was freshen the motor - new gaskets, plugs, wires, the essentials - then drove the piss out of it. Had a microswitch wired up and triggered by his throttle body lever to trigger nitrous at WOT. I've never felt a stiffer clutch than it that car though.