[DeTomaso] Aluminum Exhaust Gaskets

[Chris Difani]

Bob:

There's two ways (that I'm aware of) that aluminum has been used for gaskets in that application. In both instances, the aluminum is pure aluminum, not any of the alloys like 6061, or 2024, and so forth. Not only does it need to be pure aluminum, it also has to be what's called "dead soft", or fully annealed. 

The first way has been as a single layer of aluminum. This application requires that both surfaces be machined such that they're flat, and smooth. That's "flat" in the machinist point of view, like flat to within one half of a thousandth of an inch across 12 inches of surface. Smooth needs to be to the same definition. Since aluminum, even pure, and "dead soft" isn't nearly as pliable as the usual gasket material, the user must take unusual care not to exceed the gasket's 'sealing' capabilities.

The second way I've used aluminum gaskets, is as a series of layers of aluminum. Almost like aluminum foil. My header gaskets are made up of 20 layers of formed pure, "dead soft" aluminum sheets. Each of the layers are formed to the exact outline, and profile, then all the foils are attached together at 3 or 4 points across the entire gasket. The idea is that as the bolts are tightened up, the aluminum will pressure-form to fit the two faces (header flange, and head). 

The header gaskets that I have are labeled "the last header gaskets you'll ever have to buy", and from my experience, I've got to agree with their advertising. The collector gaskets I'm using are copper, rather than aluminum... so I can't speak to that particular application.

Hope this helps,

Chris

Chris Difani
'73 L #5829 "LITNNG"
The Electric Pantera
Sacramento, CA
Email: cdifani at pacbell.net 


--------------------------------------------------------------------------------


----- Original Message ----- 
From: "Bob Timma" <ddbt10 at msn.com>
To: "detomaso" <detomaso at realbig.com>
Sent: Friday, December 26, 2008 12:06 PM
Subject: [DeTomaso] Aluminum Exhaust Gaskets


> 
> Anybody have any expirence with aluminum exhaust gaskets? I'm looking at making some for the headers to block and colectores to exhaust pipe. I have a surplus of .090" thich aluminum.Bob T.#3952
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso