Exhaust gasket needed?

[zeitgeist57]

Guys, for my FOrd 4.9L six (300ci)...do these ball-type exhaust flanges need any sort of gasket, or do they cinch right down on the rounded exhaust manifold? Could I use hi-temp RTV sealant to ensure a seal? Thanks!

http://www.columbusracing.com/forums/picture.php?albumid=669&pictureid=5918

[Steve R.]

Guys, for my FOrd 4.9L six (300ci)...do these ball-type exhaust flanges need any sort of gasket, or do they cinch right down on the rounded exhaust manifold? Could I use hi-temp RTV sealant to ensure a seal? Thanks!

http://www.columbusracing.com/forums/picture.php?albumid=669&pictureid=5918

 

Those ball and cup flanges don't need a gasket or sealer. Make sure that you have the whole exhaust lined up before you tighten it down.

[zeitgeist57]

Thanks for the fast response, Steve!

[AJ]

Use clear silicone if you want extra protection.

[zeitgeist57]

Use clear silicone if you want extra protection.

 

Clear silicone won't burn off? I was thinking of smearing on a band of RTV and letting it sit to tack a bit before bolting it on...

[gbracing81]

http://www.permatex.com/products/Automotive/adhesives_sealants/sealants/auto_Permatex_Clear_RTV_Silicone_Adhesive_Sealant.htm

 

I personally wouldn't use any sealer at all, however if you feel you need to use some I would recommend this instead:

 

http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/auto_Permatex_Ultra_Copper_Maximum_Temperature_RTV_Silicone_Gasket_Maker.htm

[zeitgeist57]

Thanks, guys! I'll just leave it dry for now.

[AJ]

clear doesn't burn off. i have no idea why but it holds up better then the high temp stuff.

[Rocky31186]

That sure is a Purdy engine block!

[Browning]

doesn't it need a donut gasket for that? Also, if he used sealant, wouldn't that be sort of a waste since that that type of connection is made to flex a bit?

[Rocky31186]

No, ball type flanges do not use gaskets. Just metal on metal. And they are made to move a tiny bit. Sealant won't "hurt" it. It's only to help seal the Metal to metal.

[Browning]

ah thanks I did not know that. Kinda funny since my s10 had that same sort of setup and I used donuts on them lol

[DavidBaustert]

I thought they used lead/graphite type gaskets?

 

Like these:

 

http://img.directindustry.com/images_di/photo-m2/exhaust-gasket-661359.jpg

[Rocky31186]

That's a completely different flange set up.

[Clifford Automotive]

My IROC had identical flanges, and they use gaskets.

[DOZZER]

Fords do not use gaskets on the ball sockets that engine.

[zeitgeist57]

My IROC had identical flanges, and they use gaskets.

 

My Corvette had flanges similar to the pic above, and used a donut gasket. It was still a shitty seal.

 

In addition, the stock cast-iron manifold for my carb'd I6 had a flat flange, with a groove that accepted the donut gasket.

 

These EFI manifolds look like they will seal just fine, provided the pipes aren't bent at the mating surface!

[Clifford Automotive]

My Corvette had flanges similar to the pic above, and used a donut gasket. It was still a shitty seal.

 

In addition, the stock cast-iron manifold for my carb'd I6 had a flat flange, with a groove that accepted the donut gasket.

 

These EFI manifolds look like they will seal just fine, provided the pipes aren't bent at the mating surface!

 

 

Yeah, the IROC has MAC headers and full exhaust on it, and thats exactly how they are. The flange is welded on not a pressed flange. So the pipe and the flange have a gap where the donut sits.

 

And now that I look at that picture again... No gasket required.