Square or round port header gaskets?
Thread Starter
Racer
Joined: Sep 2000
Posts: 485
Likes: 1
From: Dallas Texas
Square or round port header gaskets?
Been quite awhile since I messed with header gaskets. Now that I have the engine on the chassis, I need to put the headers on. I see two styles of header gaskets round or square. I have square port heads and round headers. What gasket do I need square or round?
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Originally Posted by DVG73
Come on guys this may be a dumb question but it ain't that hard to answer
Racer
Joined: Jul 2004
Posts: 420
Likes: 1
From: Lapeer MI
I've been following this thread looking for a reply too. My guess is this:
Say for example the round whole gaskets are smaller than the square. I assume this would restrict the ehaust and kill a little horsepower. I do know the exhaust is extreamly hot and if blown by something thin at fast speeds will act like a cutting torch. I suppose this would torch that gasket material to the point it's no longer restricting any flow.
So my thinking is get the gaskets that match your exhaust ports and not your headers. If you get the others you may be losing power until they burn themselves all of the way open. Good luck
Say for example the round whole gaskets are smaller than the square. I assume this would restrict the ehaust and kill a little horsepower. I do know the exhaust is extreamly hot and if blown by something thin at fast speeds will act like a cutting torch. I suppose this would torch that gasket material to the point it's no longer restricting any flow.
So my thinking is get the gaskets that match your exhaust ports and not your headers. If you get the others you may be losing power until they burn themselves all of the way open. Good luck
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Originally Posted by DVG73
... I have square port heads and round headers. What gasket do I need square or round?
Come on guys this may be a dumb question but it ain't that hard to answer
As you know header gaskets are not exactly FUN to change-out, especially with stage 8 header bolts. I've spent a considerable amount of time and money trying to eliminate header leaks, so I cannot agree with your thinking that this is a dumb question or that it's easy to answer.
Let us know what the outcome is.
Melting Slicks
Joined: Jul 1999
Posts: 3,030
Likes: 17
From: White Pine / Dandridge TN
I've been chasing a leak ever since I installed Dynomax ceramic coated headers a few years ago. I went with copper gaskets and some high temp silicone. I think I used square gaskets, but no positive, because they most closely matched up to ports on the heads. The headers are D shaped I think. Anyway, on the side where I used copper gasket and high temp silicone I've had no leak. I'm also using Stage 8 header bolts. Now I just need to do the drives side but as the previous post said, working on headers is a pain in the a$$.
Drifting
Joined: May 2003
Posts: 1,634
Likes: 2
From: Melbourne, Victoria, Australia, the World
I have large port heads and a set of headers I made myself to suit RHD. I do not use gaskets but used just ordinary silicone to seal them. 2 1/2 years later they still do not leak. I actually used the clear stuff and have had no problems with it. No need for the high temp stuff.
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Thread Starter
Racer
Joined: Sep 2000
Posts: 485
Likes: 1
From: Dallas Texas
Thanks for the replies. Headers are such a PITA, I am going to go with copper gaskets and I bought those high dollar Stage 8 bolts to try and prevent the gasket blow outs and self loosing bolts.
Drifting
Joined: Nov 2000
Posts: 1,536
Likes: 10
From: Sault Ste Marie Ontario
You are correct. Square ports on heads will leak with round prot gaskets. Use Round port gaskets and you will not have a problem. This is speaking from experience. I would not wory if the round gasket poses a small restriction as this will burn off quickly. Good Luck
Intermediate
Joined: Oct 2014
Posts: 37
Likes: 1
I noticed a third option... oval ports... it's hard to tell but the previous owner's mechanic used RTV instead of a gasket... i had ordered round hole gaskets and when i pulled the headers loose it appears that they're more of an oval... certainly not a "D" and certainly not square... same for the ports on the heads... they appear oval too.. Can't find oval gaskets locally so i was about to try these round ones and see if they'll seal... just curious if anyone had run into that
