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FE Power Forums => FE Technical Forum => Topic started by: jimeast on August 17, 2015, 08:21:24 AM

Title: Head Gasket for 390-445 Build
Post by: jimeast on August 17, 2015, 08:21:24 AM
I'm in the early stages of a 445 build.  I'm using C6AE-R heads iron heads.  My question is around the head gasket.  The chambers of the C6AE-R heads open up slightly more than 4.080 in several places and the cylinder bores will have chamfers that are more than 4.080 in diameter at the top.  Assuming a zero-deck, Is there anything to consider when you have a situation where the gasket bore diameter is slightly smaller in some places than the chamber diameter or chamfer diameter on the bores?

Also, it looks like for 4.08 bore diameter, Cometic is the only choice in 4.08 that comes up on Summit.  Any other head gasket choices I should consider?
Title: Re: Head Gasket for 390-445 Build
Post by: fairlanegt427 on August 17, 2015, 08:46:15 AM
i am running a cometic on my 428 and have had no problems with it.  at first of using them i was skeptical but after you install and get to temperature you do have to retorque the heads,  they werent leaking at all but cometic wants a retorque.  but that was with aluminum heads and not iron like your using,  but i still do not see why you shouldnt retorque them just to have that piece of mind. imo :)
Title: Re: Head Gasket for 390-445 Build
Post by: Stangman on August 17, 2015, 10:03:07 AM
I run felpro-1020 used them about 5 times never had a problem
Title: Re: Head Gasket for 390-445 Build
Post by: blykins on August 17, 2015, 10:54:34 AM
You can not have the gasket hang over into the bore.  Even if you didn't have the chamber/relief issues, you do not want a head gasket the *exact* size of the bore size. 

As the others mentioned, the Felpro 1020 is an excellent choice for most FE's.  If you need a specific thickness, then a Cometic gasket will work.
Title: Re: Head Gasket for 390-445 Build
Post by: jimeast on August 17, 2015, 11:17:44 AM
As far as I can tell, the Fel-Pro 1020 only comes with a 4.400" bore.  Is it OK to use a gasket diameter this large with a with a 4.08 bore build?

You can not have the gasket hang over into the bore.  Even if you didn't have the chamber/relief issues, you do not want a head gasket the *exact* size of the bore size. 

As the others mentioned, the Felpro 1020 is an excellent choice for most FE's.  If you need a specific thickness, then a Cometic gasket will work.
Title: Re: Head Gasket for 390-445 Build
Post by: blykins on August 17, 2015, 11:40:53 AM
Sure.  Just as long as you take into account the gasket bore and thickness for your particular application.
Title: Re: Head Gasket for 390-445 Build
Post by: 57 lima bean on August 17, 2015, 11:42:15 AM
Always ran the 1020 Gaskets with my 428.This had the R heads with CJ valves.Worked well.
Title: Re: Head Gasket for 390-445 Build
Post by: turbohunter on August 17, 2015, 12:07:29 PM
Hey guys I realize that the Felpro 1020 has always been the default gasket on the FE forever.
For me having a 4.40 bore on a small bore engine isn't the best. I hate having that gap between head and bore. Sharp edges get hot. Maybe detonate easier.
The surface material for me is not up to date. I have seen quite a few cases of oil capillary action (and I'm not a builder).
The water passage fit on certain FE blocks is less than perfect.
And the oil metering holes on todays builds is useless if you meter the oil elsewhere (which is normal nowadays) and contributes to oil migrating under the gasket.
I get it, they work on lots of builds. But I don't think that gasket is a panacea and your particular build should be entered in the equation.
Full disclosure. My brother is a gasket manufacturer.
Title: Re: Head Gasket for 390-445 Build
Post by: blykins on August 17, 2015, 05:28:10 PM
Ask your brother if he can cut me out a pair of head gaskets, 4.400" bore, .034-.035" thickness.  Cometic has had my order in for 2 weeks and they're saying 2 more.....getting tired of waiting.
Title: Re: Head Gasket for 390-445 Build
Post by: turbohunter on August 17, 2015, 06:07:01 PM
I'll get you two in touch.