Header bolts
 

So I'm guessing stock 5.0 bolts don't work with Martins headers? I went to test fit today and can't get a few of the bolts in as the heads don't clear the tubes. What are you guys using/suggest?

Turns out the stock bolts heads are too big since Martin has changed the tubes to 1 5/8". New bolts on the way. )

IF they fit your headers without interference with the tubes (they do on most Ford applications 1-5/8" or smaller), these will NEVER loosen up and cause the dreaded "tick tick tick" exhaust leak: http://www.summitracing.com/parts/STG-8913A/

You'll need a 12 point socket to install them, but these have nice, small heads for clearance and they're stronger than grade 8. They are drilled for safety wire to keep them from loosening: http://www.summitracing.com/parts/ARP-400-1205/

Here's one more type of locking design that may be worth considering: Percys Vibe-Lock Header bolts - Free Shipping on All Orders @ JEGS

I checked those out. Martin is using some 12pt 3/8" bolts. I'm getting a set off him to try. Maybe they are like the ARP's you linked to. Will find out soon.

Well I test fit my headers again last night. The new 3/8ths 12pt bolts don't work very well. 3 bolts on each side are too close to the pipe to get a wrench on. A socket is out of the question so I took a 12pt box wrench and ground it down thin and still couldn't get on a couple of those bolts. Looks like I'll have to go to a hex head so I can at least get an open end wrench on them.

Ordered some 5/16" hex head bolts from Summitt. They work...still a little tight on the inside curves but they'll work with an open end wrench.

Getting bolts to fit on tight header can be a real pain in the neck. a few tricks can make it a lot easier. Especially those that are inside a curve of the pipe.

Use a couple of ball peen hammers and slightly dimple the header tubes next to the bolt heads. Only about a mm or two. not enough to effect performance.

Start the end bolts into the heads, by 1-2 turns. Then start all the other bolts. go down the line and tighten each one by 1-2 turns. That gradually brings the flange into the head surface evenly, so none of the bolts are sticking out past the flange too far.

Grind down a 7/16" wrench so the ends are pretty thin. You can use that to tighten the bolts down, but not for final torque.

This is the only set of header bolts I've used on all 7 of my Monster Miatas


ARP 400-1108


No dimpling, not grinding down tools, no clearance issues at all.


Bill S.

PS: I do put a drop of locktite blue on each one to play it safe, never had an issue with them coming undone.

I used the basic 3/8 head hex fastener so I could get an open end wrench on those tight ones.

I'm curious about your header gasket. My original gaskets went too far down and the tube part of the flange did not hit them much if at all causing a leak. It was like the header tube is too high compared to the gasket. I replaced those gaskets with the Percy's aluminum ones that I believe are thick enough and soft enough to actually seal at the tube flange portion as well as the flange itself against the head. Been "re-torquing" the bolts regularly...

Mike

I've used both the Percy and the Felpro 1415 with longevity in mind. I torque them once, then off for a quick 2-4 mile ride to heat cycle them. Check the torque, then do not touch them again. With the Locktite blue, I've rarely if ever had to deal with a retorque again

It does help to check the heads and the headers for level before putting them together. I have had to put the header flange on a large belt sander to take care of minor high spots in the past.

Bill S.

Thanks for the tips guys. I did do the "start all the bolts and tighten incrementally" but still could not use a socket on a couple of them. Maybe I need to look for a thin wall 5/16" socket....that would likely do it.
Bill these are the bolts i have.
The Official ARP Web Site | Kits
They appear to be the same as yours except 1"uhl. Not sure why the big difference in price.

Mine are shorter so they do not bottom out in the head, yours at 1" are close to bottoming out.

Mine are also stainless, which is why they cost more. I believe in doing it once, doing it right, and not having to deal with doing it over again because I cut corners the first time.

Some call it being anal, I call it being efficient.........

Bill S.

I hate rusted bolts. I hate painted bolts. Almost every single fastner I'm using is stainless, and I will use blue loctite only. Hate the red stuff. At work, all our equipment gets painted tip-tail and ever bolt, hose, and fitting gets it too, so I have to chip it all to remove fastners. Annoying.

I have a set of these I've used for very tight 12 point bolts. I'm not 100% sure it would have worked in the end, its the equivalent of a 1/3 cut on a 12pt box.
Snap on Crows Foot Set PAK435430 | eBay

With me it's called not knowing any better. Definitely not trying to cut corners here. Are the bolts I have prone to rusting? The bolts Martin sold to me were 1" so I thought I was safe ordering the ones I got.
So the original bolts didn't work, the 12pts Martin sent didn't work, the ones I just got are now questionable. JHC, I guess I'll be looking into a 4th set of header bolts.
On second thought I'll see how these go, and change them out when neccessary.
Thanks.

Painted header bolts will eventually get surface rust on them once the paint flakes off. Otherwise, they should be fine.

As for the length, I've just learned from past experience that the longer bolts sometimes bottom out on a stock set of heads, and then back out and become loose over time. Not always, but for me, I ask myself the following question time and time again "why take a chance". Then again, I ask myself that question all the time, on every car I'm working on where I see the quality items and the lesser quality items side by side on the web page I'm ordering them from.

Bill S