rice_classic

During the replacing of an exhaust manifold a couple of the studs actually unscrew out of the head. This is no big deal because they screw right in... well, as my roomate screws them back in he strips the head.!! Damn him!

Now I can buy a larger die/tap (which is it called?) and re-thread the hole but won't I need oversized studs? Where do I get oversized studs?

I actually need them right away unless you all think the header will be safe with just one stud missing.

vitrox

same thing happened to me.. but I only have one bolt left holding it on.. don't matter to me as long as its sealed. I'll replace it all eventually anyways.

XrcR6

Might not be too bad in short term if its one of the inner and lower row of studs.

You could tap (this is the one to thread holes) it for something bigger since its stripped and even use an English/SAE stud since it may be easier to find. Not too big a deal since you shouldn't need to remove it. But kinda a pain since you'll initially might need to enlarge the gasket and header flange hole for that stud. And each time you remove the header it will be 10mm-10mm-10mm-10mm-ugh @#%$ 1/2inch-10mm-10mm... (10 or is it 12, I forget...you get the point)

If your roommate didn't strip it too bad, you could just try cleaning it out by running the same size tap through there. But you need a metric tap of the correct size/pitch... Try http://www.mcmaster.com/ or some other Internet place.

If that doesn't work, you could fill the hole with JB weld/some kind of aluminum epoxy and just re-drill then re-tap it for the original size.

Or you could try a Helicoil (http://12.130.38.20/products/helicoil.html), which would repair it and keep the same stud too.

rice_classic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by XrcR6 &raquo;</TD></TR><TR><TD CLASS="quote">Might not be too bad in short term if its one of the inner and lower row of studs.</TD></TR></TABLE>

Great deal of help, but it's not a lower inner one, it's an upper outer one on the top right. But it's the only one and it is in there at 23 ft/lbs but will want to turn more if I try to torque it to the correct 25 ft/lbs. It's on my race car and I hope it will be fine for the race this weekend.

Another question, why do I have to have a stud? Could I just tap it and buy a bolt that would fit?

XrcR6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rice_classic &raquo;</TD></TR><TR><TD CLASS="quote">...it's an upper outer one on the top right....

Another question, why do I have to have a stud? Could I just tap it and buy a bolt that would fit?</TD></TR></TABLE>

Hmm, you know I recall losing the lower rightmost one after doing some work and I even did a time trial on it (unknowingly). I guess it comes down to how thick the header flange is, how straight/flat it is and how good a seal you get with it & the gasket to the exhaust ports. I didn't seem to have leak when it happened to me.

I've always wondered the same thing stud/nut vs bolt. From a design principle I surmise since you occasionally need to remove the manifolds, this one-degree of separation is better than having some kind of steel bolt threading into the softer aluminum head each time. Additionally, you have less to worry about galling/seizing, since the nut/stud are probably similar metals. Also, its easier to fit a manifold on studs vs having to line it up to holes.

So yeah, that would work just be aware of the caveats above.

rice_classic

I could not have asked for better help!

Thank you much!