C2 Exhaust Manifold to header pipe mounting studs

[Donald H.]

I have new studs and Stover nuts. I put the studs in the exhaust manifold with some high temperature anti-seize. The studs have 1/2" of thread at the top, then a gap then threads (first picture attached). I got these from LIC because they are magnetic which I though would be better for judging.

My problem is that the studs do not stop screwing into the manifold at the gap. When I try to screw on the Stover nuts, the studs just keep screwing up into the manifold and come out the top.

The second picture is of the studs that Paragon sells. Note that instead of a recessed gap between the upper and lower threads of the ones I have from LIC, there is actually an area that is the same diameter as the threaded section.

Has anyone used the LIC studs, and if so how do you get them to seat in the manifold and not just keep screwing up into the manifold?

BTW: I have ordered a set from Paragon today even though they are SS and will likely take a small judging hit.

Thanks,

Don

[Gene M.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Don
Neither of the pictured studs is correct. The central solid stock diameter should be a few thousands larger than the OD of the thread. The unthreaded central portion s/b about twice as long as pictured. The black one isn't even in the same ball park. Originals were not machined they were cold drawn.

[Donald H.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Don
Neither of the pictured studs is correct. The central solid stock diameter should be a few thousands larger than the OD of the thread. The unthreaded central portion s/b about twice as long as pictured. The black one isn't even in the same ball park. Originals were not machined they were cold drawn.

Any idea where to buy more correct ones?

Thanks,

Don

[Michael M.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Any idea where to buy more correct ones?

Thanks,

Don

Check Corvette Central. I got their stud/nut set # 321027 along with a N11 exhaust system several years ago. Not exactly correct, but close.

[Donald H.]

Re: C2 Exhaust Manifold to header pipe mounting studs

I'm actually installing a CC N11 system now. Their studs don't look to have a short unthreaded middle section just like the ones Paragon sells.

Don

[Michael M.]

Re: C2 Exhaust Manifold to header pipe mounting studs

I'm actually installing a CC N11 system now. Their studs don't look to have a short unthreaded middle section just like the ones Paragon sells.

Don

Both the long and short studs have unthreaded shoulders to bottom out the studs. Here's a pic of CC's studs I have - they look a little different from the current pic online.

[Donald H.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Both the long and short studs have unthreaded shoulders to bottom out the studs. Here's a pic of CC's studs I have - they look a little different from the current pic online.

Yes, yours looks more like what I think Gene was describing. When did you purchase yours?

Thanks,

Don

[Joe L.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Yes, yours looks more like what I think Gene was describing. When did you purchase yours?

Thanks,

Don

Don------


I only use stainless steel studs for the exhaust manifold, correct or not.

[Michael M.]

Re: C2 Exhaust Manifold to header pipe mounting studs

Yes, yours looks more like what I think Gene was describing. When did you purchase yours?

Thanks,

Don

I had to look it up - I got them in 2011 - a little longer ago than I thought.

It's not a great picture, but if you look close at the current CC pic, they both have a shoulder.

[Gene M.]

Re: C2 Exhaust Manifold to header pipe mounting studs

The lower stud in Mike's photo is good . Notice the unthreaded section in the mid section is a bit larger diameter than the thread OD. This will allow it to bottom out against the exhaust manifold as it should.

A good suggestion to seek out stainless studs as this is a bad area to readdress once rust takes hold of the parts. Be advised that stainless on stainless (studs & nuts) will gall easy so use an anti seize compound.