Header bolts/studs clearance issues
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
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From: Bogart GA
Header bolts/studs clearance issues
I have a set of 1-3/4" primary tube headers. I have studs but the only nuts that will clear the tubes are the 12 point nuts (I had to even grind down the dia of several of those). trouble with these is ya can't get a wrench around some of them very well because the tube is to close at some locations. They don't make open end 12 point wrenches for obvious reasons. I did make one that work well enough to just snug them but it broke. I found a set of bolts with small hex heads and the centers have internal hex wrench capability as well. Should I ditch the studs? The 12 point were major PITA!! I thought about dimpling the tubes but I really don't want to do that. I am also concerned about bolts eventually stipping out the aluminum heads. What is the trick here? Some people somehow use 1-7/8" tubes...don't know how they do it.
Intermediate
Joined: Dec 2006
Posts: 46
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From: Connecticut
Studs
What size are the studs you have already. We use 3/8 " studs with a 1/4-20 center section on our modified.The nuts are only 7/16 and cake to get to.
Just to clarify a bit, the section that goes into the head is 3/8-16, it then has a turned down section where the nut goes on which is only 1/4-20,this portion sticks out past the header flange.
Just to clarify a bit, the section that goes into the head is 3/8-16, it then has a turned down section where the nut goes on which is only 1/4-20,this portion sticks out past the header flange.
Last edited by TotalC1971; Jun 12, 2007 at 10:50 PM.
Thread Starter
Melting Slicks
Joined: Nov 2000
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From: Bogart GA
Not sure, what do you use for washers? the holes in my flange are fairly big. Are you using the "stepped" studs? If so do they have a shoulder with which to locate the header flange?
Intermediate
Joined: Dec 2006
Posts: 46
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From: Connecticut
Yes they are stepped.The shoulder goes through the flange. The nuts we use have a "lock washer" (for lack of a better term, Im sure youve seen them) molded to the nut,like a big flare. Had plaenty of headers totalled, never had a nut let go.The flare o nthe base of the nut is bigger than the 3/8 hole for the header flange.
I see from the pics of your engine build the studs are 3/8-16 all the way through.Your nuts are the same size and even though they may be the smaller 12 point they dont compare in size to the 1/4-20. Ill see if I can find where we got them,its been so damn log, we just keep reusing them!
I see from the pics of your engine build the studs are 3/8-16 all the way through.Your nuts are the same size and even though they may be the smaller 12 point they dont compare in size to the 1/4-20. Ill see if I can find where we got them,its been so damn log, we just keep reusing them!
Last edited by TotalC1971; Jun 12, 2007 at 11:05 PM.
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
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From: Bogart GA
Thanks for the info, I have seen that type for sale at Summit racing but was unsure of the issues you just have clarified for me. I think they were Mr Gasket. Thanks for the help! This has been one of those nagging issues that I am glad to be rid off! I am ordering a set this morning!
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
You have to get the universal 5/16th hex nuts for the ARP studs.
Then you also have to round off the shoulder and grind the side off some of the washers - Aren't custom motors fun
That is Permitex red high temp. The nuts never get loose.
Then you also have to round off the shoulder and grind the side off some of the washers - Aren't custom motors fun
That is Permitex red high temp. The nuts never get loose.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
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From: Orlando Florida
St. Jude Donor '05
You might have to take an angle grinder to the wrench like I did... hope you can see on the photo how thin the ring is ... it's tight but it fits. I'm using Breslin locking bolts with a12 pt head. These are 1 7/8" primaries.
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Safety Car
Joined: May 2001
Posts: 3,758
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From: Surrey
My headers are 1 5/8" primaries so maybe this wont apply. I didn't bother with studs, locking nuts, or any of that fancy stuff, I just went down the local hardware store & bought a handful of allen head (3/8" UNC?) set screws in stainless, along with some stainless spring washers. I then measured the depth of the threads in the holes in the head (by screwing the setscrews in by hand as possible), added the width of the header flange, subtracted about 1/8" (to avoid bottoming out) & then chased out the threads with a 3rd tap. Using copper gaskets I fitted the headers, was able to get to the screws with an allen key to tighten them all easily (spring washer under each), heat cycled it a few times & then checked the screws for tightness. I've not had to touch them since (4 years?). Stating the obvious, final tightening each in turn, a bit at a time, starting from the centre & working out. Nuts on studs are a pita when access is tight, allen heads are far easier, but the downside is that if you strip a thread it's not going to be a nut/stud, its going to be the thread in the head (either don't overtighten them, or buy a helicoil set!).
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,738
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From: Bogart GA
Thanks for the replies. The 3/8" 12 point just will not work with my headers. I also had to grind almost the entire flange of the nut just to get them on. No way to get a wrench completely around them. Some locations were not a problem. Like hex cap screws...tried that as well, work fine in some locations but there was a couple that the way the tube was bent there was no way to access the bolt from the top with a hex key wrench. I think the bone head header manufacturers need to let you know that standard fasteners will not work and recommend a type to use. A stainless set of ARP studs cost big bucks!! but I guess if all the after-market dealers were to give you all the "facts" about their " bolt-in" products, we all would be driving around stock Vettes. This is a big reason why our car budgets usually end up off the scale over the top.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I also have a set of 12 points that I had dorked with to make them work. Well them and a set of 6 point ARP head studs are sitting in their boxes.
6 point head studs or bolts can not be used with 1.56 diameter springs on your heads.
You can clearly see in my picture abobe that you are not even going to get a 12 point open end between the stud and the pipe - They are Hooker 1 3/4
6 point head studs or bolts can not be used with 1.56 diameter springs on your heads.
You can clearly see in my picture abobe that you are not even going to get a 12 point open end between the stud and the pipe - They are Hooker 1 3/4
Last edited by gkull; Jun 14, 2007 at 08:38 AM.
Le Mans Master
Joined: Oct 2004
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From: Orlando Florida
St. Jude Donor '05
ARP or Breslin make the external 12pt smaller so that a wrench fits or at least almsot fits... with 1 3/4 or 1 7/8 primaries this can be a very tight fit.
You could try the internal hex bolts, they sell them at the local 'zone'....
You could try the internal hex bolts, they sell them at the local 'zone'....
Racer
Joined: Oct 2005
Posts: 469
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From: West Slope of the Sierras California
Here's my story...
PO had a mix of allens and standard hex header bolts. The hex were inside on 1, 2, 7 & 8, due to inward angle of the tubes on the Hookers. Only able to use 7/16 open end on the hex header bolts, could never get them tight enough, always loosening(on alum. heads). Bought ARP SS 'small' flange header bolts, they have a smaller head, use 3/8 wrench. I use 1" length on all but inside 1, 2, 7 & 8 where I opted for 3/4" length. Now I can use box-end on all.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Safety Car
Joined: May 2001
Posts: 3,758
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From: Surrey
Another option, if you're running nuts & studs, is to use reduced diameter nuts. Haven't a clue where to buy them, but if you've got a lathe, or drill press, & a tap you can modify some stock full nuts. Assuming the reduced part of the stud is running a 5/16 thread, then buy some 1/4" full nuts (7/16" AF as opposed to 1/2"AF with 5/16" UNF/UNC), use a lathe or drill press to run the correct drill bit through them & then run the appropriate 5/16" tap through them. It may just allow you to get a wrench of some sort onto them.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
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From: Orlando Florida
St. Jude Donor '05
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Well how about the other thing? installation being a snap. I was just in Orlando for a week. I should have figured out how to meet up. The Orlando has to be the biggest square footage convention center that I have ever seen.
Le Mans Master
Joined: Oct 2004
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From: Orlando Florida
St. Jude Donor '05
Let me know next time you're visiting Orlando ... did you have a good time here ?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I've changed out my motor so many times that I have tried to simplify as much as I can. Fully studded motors are a must have item. This last motor build I even studded the oil pan.
The manual tranny cross shaft like our Keisler kit is very easy to remove.
1. Remove the firewall spring & lower cross shaft spring
2. clutch petal rod nut - off
3. frame end of the cross shaft ball joint nut - off
4. remove the cross shaft
Then the headers can come on or off.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Last week I had a work seminar in Orlando. I flew in the previous week to meet with friends in the Daytona. Where I did all the touristy stuff like Daytona international speedway, Daytona beach, Kennedy space center. Then I did the cruise on down to the Fort Meyers area. I even did hours of road rally action out in the middle of nowhere on the sea shell coated sand roads just for the fun of it kind of out in the Sebring area across on I-70. You have to test the rental cars
I put nearly 800 miles on my rental car and drove nearly everywhere at 90+ mph. Rain or shine, I was very lucky. Every time I ever saw a trooper I was either slowed down for traffic or they already had somebody stopped. Your freeways and highways are really nice compared to much of the US.
I would own a fast car in Florida. I can see why you see so many Vettes driving around. Great weather.
Last edited by gkull; Jun 14, 2007 at 02:47 PM.