Stock Manifolds Vs. Headers
Thread Starter
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Stock Manifolds Vs. Headers
Why do the stock manifold stay in place for its entire life and not leak around the gasket but if I put a set of headers on my car, the bolts will back off and leak within 200 miles and require constant attention?
My son ask this question of me this evening. We put long tube headers on his car this weekend and he was having to tighten the bolts already this evening. Only thing I could come up with is the flange thickness. The headers we installed were SLP brand and they have a substantial flange.
My son ask this question of me this evening. We put long tube headers on his car this weekend and he was having to tighten the bolts already this evening. Only thing I could come up with is the flange thickness. The headers we installed were SLP brand and they have a substantial flange.
Le Mans Master
Joined: Apr 2005
Posts: 6,350
Likes: 423
From: Seattle Area WA
I would guess that it's a matter of expansion and contraction differences between the heavy cast iron manifolds and the headers.
The headers will cool faster and contract faster than the heads and each time the bolt has a chance to back off. Stock manifolds are installed without a gasket so there is equal thermal transfer between them and the heads.
Stock manifolds also use french locks on them.
I'd install a set of Breslin fasteners and be done with it or a set of Percy hi crush gaskets that should help prevent this.
The headers will cool faster and contract faster than the heads and each time the bolt has a chance to back off. Stock manifolds are installed without a gasket so there is equal thermal transfer between them and the heads.
Stock manifolds also use french locks on them.
I'd install a set of Breslin fasteners and be done with it or a set of Percy hi crush gaskets that should help prevent this.
Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
I'm back!!!
I just spent @ $100.00 on a flex head 1/4 in wratchet & a crows foot 3/8 to keep my header bolts tight .... NOTHING i've ever tried keeps them tight... So I gave-up & bought the set-up that gets to all my header bolts from topside
I just spent @ $100.00 on a flex head 1/4 in wratchet & a crows foot 3/8 to keep my header bolts tight .... NOTHING i've ever tried keeps them tight... So I gave-up & bought the set-up that gets to all my header bolts from topside
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Earl's graphite gaskets with summit headers bolts, beware the bolts have a surrated/nurled undersite and bit into ceramic coating a touch. You do have to tighten them after a heat cycle but once your do that they pretty much stay put. No leaks to speak off everytime I have used the Earl's grahite gasket
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
I'm using the same cheapo summit headers, they don't have that thick of a flange, but they haven't loosened on me much since installing them.
Of course what I really love about them, besides the price, they fit PERFECTLY! Oh and they cool off pretty damn quick, so doing an oil change isn't too bad.
Of course what I really love about them, besides the price, they fit PERFECTLY! Oh and they cool off pretty damn quick, so doing an oil change isn't too bad.
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Thread Starter
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
We have a set of Stage 8 fasteners we are putting on it but was just curious as to why they loosen.