header bolt help.....
Thread Starter
On The Tree
Joined: Oct 2008
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From: Aurora, IL
header bolt help..... I just got my LPP stainless headers, and they look pretty nice, but now I need header bolts, what did you guys use since the flange is so thick?
I am thinkin it needs to be a 3/8" grade 5.....and needs to be about a 1-1/4" long right?
I am thinkin it needs to be a 3/8" grade 5.....and needs to be about a 1-1/4" long right?
WOW, that is a thick flange. I'd think you'd need 1.25 bolts. Buy a standard Allen head bolt that's 1.25 inch UHL and see if if works. If yes, order a few packs of ARP 613-1250 stainless 3/8 bolts with 12 point heads. Sorry! You'll need three packs at $18.69 each!
Stainless steel 12 point bolts are the only way to go with headers. As deep as you can get them into the head. They won't loosen up if done right (read: good and tight). You won't need to fool with those PITA Stage 8's.
You are going to use copper header gaskets, right?
Stainless steel 12 point bolts are the only way to go with headers. As deep as you can get them into the head. They won't loosen up if done right (read: good and tight). You won't need to fool with those PITA Stage 8's.
You are going to use copper header gaskets, right?
Last edited by Paul Bell; Oct 7, 2008 at 09:04 PM.
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Verdad Gallardo Thread Starter
On The Tree
Joined: Oct 2008
Posts: 110
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From: Aurora, IL
hmmm, it'll be tough to get the wrench onto a few of those bolts as some of the tubes pass pretty close to them. Worth a try though, plenty less money than the ARP kits. I'd also worry about stripping the Allen sockets, stainless can be pretty soft especially after heating and cooling cycles. Can't go wrong with the 12 points but if it can be done for less bucks, go for it.
The whole thing about header bolts on any engine is to get them threaded into the head as deep as you can. This will reduce/prevent them from backing out. I'd say that as close to three-quarters of an inch thread engagement into the head is needed. One inch bolts through a half inch header flange would only sink it into the head a half inch. They'll back out. Natch, a three-quarter inch bolt on the OP's headers will result in a quarter inch engagement. He'll strip the threads in his heads before they're tight enough,
An inch and a quarter bolt should do the trick.
An inch and a quarter bolt should do the trick.
TECH Fanatic
Joined: Nov 2007
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From: Lansing, MI via Bowling Green, KY, Dalton GA, Nashville, TN & Atlanta, GA
I used 1" stainless steel Breslin Split Lock bolts on my Kooks. I believe Percy's makes them now as the Breslin founder passed away. If you want a locking bolt, those are a much nicer design than Stage 8's. They actually won a few engineering awards. I've never actually heard of anyone using anything longer than 1". 3/4" would be too short, imo.
Thread Starter
On The Tree
Joined: Oct 2008
Posts: 110
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From: Aurora, IL
hmmm, it'll be tough to get the wrench onto a few of those bolts as some of the tubes pass pretty close to them. Worth a try though, plenty less money than the ARP kits. I'd also worry about stripping the Allen sockets, stainless can be pretty soft especially after heating and cooling cycles. Can't go wrong with the 12 points but if it can be done for less bucks, go for it.
they look like this
http://www.chinatraderonline.com/Fil...3400026982.jpg
TECH Fanatic
Joined: Nov 2007
Posts: 1,745
Likes: 18
From: Lansing, MI via Bowling Green, KY, Dalton GA, Nashville, TN & Atlanta, GA
The Breslin bolts I mentioned earlier are also 12 point. I had to grind down a 3/8" wrench to get on some of them. I think ARP makes a 1" stainless bolt with a 5/16" head.
Thread Starter
On The Tree
Joined: Oct 2008
Posts: 110
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From: Aurora, IL
the problem is, with the large bolt head, it gets difficult to get a wrench on there next to the middle primaries.
you can only use a socket on a select few bolt holes. the primaries, are just there in the way a lot. I know with the hex wrench or socket, they are long and skinny and can get up inbetween primaries without a issue
you can only use a socket on a select few bolt holes. the primaries, are just there in the way a lot. I know with the hex wrench or socket, they are long and skinny and can get up inbetween primaries without a issue
