choosing head gaskets

[4g63turbo84]

I could use some help choosing a good head gasket... and just so you'll know the head and block will be machined perfectly flat..

 

[awdtalon4451]

You could go Mitsu "MLS" but ive always ran the Felpro Perma-Torque

 

[viperlp01]

He is non turbo but the permatorque for the 420a is also a good choice.

 

[4g63turbo84]

I have a 420a for ar that im driving but im building a 4g63... and the head gasket im needing is the one for the 4g63

 

[WES_393]

If you wan to use MLS, the head and block not only have to be resurfaced, but must have a surface finish of 50 RA. That's basically a mirror finish on both head and deck. Composite gaskets along with ARP studs have been known to hold over 500hp, but of course a good tune makes all the difference. So it depends on your goals.

As for brands? When it comes to composite, Felpro is considered equal to Mitsubishi. I wouldn't use anything but those two. For MLS, I would suggest Felpro Perma-Torque over Cometic. Felpro seems to have a much better track record for MLS gaskets.

 

[BogusSVO]

Good that you know that the head and block need to be surfaced for MLS.

Like WES stated, they have to be about slick as glass.

The machine shop you use must have the equipment to cut this finish.

Do you know what equipment will be used on your head and block?


http://www.dsmtuners.com/forums/cyl...0613-why-not-let-your-head-belt-surfaced.html

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

http://www.dsmtuners.com/forums/cyl...-deck-4g63-cast-iron-block.html#post152790451

http://www.dsmtuners.com/forums/cyl...correction-machining-belt-surfaced-block.html

 

[LandoAWD]

What are your goals?

 

[gprix1]

I can definately vouch for the surface finish needed for MLS. I made the mistake of thinking it was a bit over-hyped needing such a finish for MLS. I had read where some guys posted they ran an MLS with a standard finish and no problems so I wrote it off as being overly anal to bother with all that. Went ahead and installed the $200 Felpro permatorque with standard ARP's torqued to 90lbs on a standard finished block and head for my 2.4L build.
Worked fine with zero issues during breakin but once I turned up the boost to 18psi I started having overheating issues forcing me to run the fans most of the time, shroud the IC to the radiator (a good thing), even blasting the heater sometimes in the summer; it was a constant battle.
After some time I could see black carbon deposits in my overflow bottle and when I pulled my plugs, #2 had some oil and coolant on the threads. Mind you I wasn't really losing a measurable amount water or oil but still, clearly the seal was not 100%. The combustion gases were somehow finding their way to a coolant passage and super-heating the water... and it was getting progressively worse over time.

Finally, I did more research and discovered the MLS wasn't really necessary for me since I would never run more than say 24psi on my pump gas, daily driven car. If you keep your knock in control and clamp it down with good head studs, an OEM composite can hold that much boost no problem. This was good news since I really didn't feel like pulling out my entire engine and stripping it down to take back to the machine shop. So, I purchased the MAP ultimate duty head studs and an OEM 4G64 DOHC (running a 4G64 block) composite gasket. Clamped it down to 100psi and have had zero issues ever since. In fact, I run almost too cool now with my sealed IC-to-radiator, 3-core Koyo radiator, modified OEM fans to fit, and vented hood. After doing all that, the real problem all along was not trusting what these guys were saying about the proper prep needed for an MLS gasket.
Ultimately, choosing the right head gasket comes down to what LandoAWD asks in the post above this one:

What are your goals?

 

[jed344]

i am also in same boat and am doing arp and felpro route ik a guy who ran 28psi on e85 with that set up all day no issues yet.