Head Gasket?, what head gasket Options

[d0w0rkS0n]

Hey guys, almost ready to boost my 7a. i noticed the Head gasket size is 81mm. all the head gaskets im finding is 87mm and 89mm from Cometic. what head gasket do yall recommend? anything else? what should i do?



any adviced will be greatly appreciated.

thanks!


Allen

[presure2]

Hey guys, almost ready to boost my 7a. i noticed the Head gasket size is 81mm. all the head gaskets im finding is 87mm and 89mm from Cometic. what head gasket do yall recommend? anything else? what should i do?



any adviced will be greatly appreciated.

thanks!


Allen

isnt the stock HG metal?

[playr158]

oem 4agze i think should work. I know its in the stickies.

[d0w0rkS0n]

stock HG is metal.. yes.


and ive red Stephs write up on her build. and apparently the 4agze isnt a 100% match.

or am i just reading wrong.

[playr158]

its not 100% but it has worked in the past.

".the 4ag(Z)e would be our choice
from a corolla or MR2 (years 1984-89) the 81mm will be the choice of bore size since the 4age and 7afe are both stock 81mm bores...they come in a variety of thicknesses..but from COMETIC GASKETS the MLS .040" thick prt # C4170-040 and cost of $83.95 is available..The Cometic MLS gasket is comprised of three layers of Stainless Steel. Cometic uses Stainless steel for increased strength, it’s ability to rebound and corrosion resistance. The
outer layers of the gasket are embossed and coated on both sides with a flouroelastomer rubber based material (Viton) designed to meet the demands of a variety of harsh sealing environments, load conditions and surface finishes. The Viton coating is heat resistant to 2500C or 4820F. The center or shim layer of the gasket is comprised of an uncoated Stainless Steel layer, which can be varied to
accommodate multiple thickness requirements. The MLS gasket is ideal for both aluminum heads to cast iron blocks and aluminum heads to aluminum blocks."

This post has been edited by playr158: Dec 31, 2008 - 10:32 AM

[d0w0rkS0n]

your awesome. so that is the one You recommend?

[playr158]

theoretically i do recommend it (i have no personal experience with it)

Hurley or oobe will be able to provide a personal recommendation, try PMing them

[hurley97]

Theoretically thicker is better if you're planning on boosting. However, using a composite headgasket instead of a metal one makes for more of a chance for the higher pressure in the cylinders to blow out the headgasket. IIRC OOBE had an aftermarket HG that was composite material that he blew out. That Cometic one sounds ok though.

I had the parts dept at work order the 4A HG just so I could compare the two. With the 4AGZE HG all the oil passages lined up just fine but all the coolant jackets were off (or it was the other way around, but I think that's right). The ones that were off did overlap so it's not like it wouldn't flow anything through it, it just would only flow say 50-60% and the flow would be disrupted by the bottleneck. I'm sure it would work just fine but I put a lot of time and money into rebuilding my engine and wasn't about to risk that when the stock HG would be just fine if not a little better. Plus changing the CR isn't necessary, just a plus if you can. I chose the safe route and didn't take a risk for an unnecessary plus.

That's how I looked at it anyway. Maybe I'm just a wuss but my boosted 7A is just fine with the stock metal HG

This post has been edited by hurley97: Jan 1, 2009 - 11:01 AM

[lagos]

I'm not a 7a guy, but having the cooling jackets not line up perfectly sounds like a really big red flag, not to use that head gasket.

[nsxtypeR]

I'll not steal this thread but what MHG is best for the 2nd gen3S-GTE in thickness? I see them from 1mm up to 1.6 mm. How to decide which one to buy?