Thread: Header Screw/Bolt Size

Well, here is my problem...

I recently bought a cheapo 2.5" header off e-bay to replace my 2" in order to make the VE breathe better. I did not have the time to install it myself, so I took the car and the port-matched header to a shop, which proceeded to forget to tighten one of the screws that connects the two pieces of the header together. The result: a whole lot of noise, backfires, and a lost screw/nut.

I guess I should do all the work on my car myself I guess... Anyway, I can probably fix it fairly easily, but the problem is I have no clue what the grade/size of the screw and nut that connects the two pieces of the header together. I also don't have access to the car up until I can go fix it, so can anyone help me out with this bolt's specs?

I'm a bit desperate and am going to a track event on Sunday. I'll only be witht the car on Saturday when auto parts stores will be closed.

Thanks

I don't have my car with me, but, off the top of my head, I believe it's M12x1.25 or M10x1.25 - I would take one of the other nuts off and head to a Fastenal or even Lowe's... They're both starting to carry a fair share of grade 8 metric stuff. I've always used the grade 8 hardware because it's plenty strong and not that much more expensive (mere pennies more).

Do you use copper or nickel anti-seize?

Harry

^^
I've never actually used anti-seize on the header. Should I? I don't take the header off very often, and the only times I did, it was to install a new one, so I never thought it mattered.

Thanks for the info. I'll look into it tonight. Unfortunately, there's no Fastenal or Lowe's around here, but I do have an auto parts store near my place that carries grade 8 screws.

I would, just because I've always thought I'd rather take the extra 90 seconds to anti-seize all the bolts instead of possibly spending 10 minutes replacing a stud later on, you know?

I've always put it on my "hot bolts" and on my wheel studs - makes tq'ing lug nuts easier.

$0.02

Not a bad idea. I may try that.

I finally found an older SSAC header in my garage (lying at the very far end of my "inventory" area) and found (by trial and error) some grade 5 screws I have lying around that will fit. They will most likely hold up, as I've used grade 5's in the past on parts that had way more stress and they held up.

Thanks for the help.

Well, I went to get the car early this morning and took the noisy/smelly drive back. It turns out that the header hanging from just one screw and the second had lost a bolt and was just hanging in the hole. I proceeded to replace all 3 screws only to notice that the two gaskets (the one to the cat and the one between the two header pieces) were ruined.

I went to a local exhaust shop and I had no trouble finding the rear gasket, and I had to get "creative" with the front one, because I couldn't find any that matched. I just ordered the metal one from summit racing, and I hope that my temporary contraption will hold until I receive it.

No more noise/smell and more pull now. Thanks for the help!