1G Center exhaust manifold stud

[97blkgst]

Alright so I will try and be detailed the best I can, I have a 1990 GSX which I have owned for a few months now but have been unable to drive as I have been making repairs/maintenance to make it road worthy.

Anyway I decided to ditch the cracked 1g exhaust manifold for a Forced Performance manifold and some ssstuds. Now my problem is my center exhaust manifold stud on the bottom will screw all the way into the hole and not stop until approximately about an inch and a half of the stud is left showing (considerably deeper than the rest of the studs) I am not sure if one of the previous owners drilled into the head and drilled to far and made it to the oil passage.

My plan was to put a helicoil in that location but my concern is metal shavings being left there even after I blow out with air and brake clean. So I guess my question is what are my options? Am I okay to helicoil it? Does the head need to come off and send off to machine shop to be properly fixed or is the head trashed?

This car is not my daily driver just a toy on the side so it's no big deal if it's the worse case scenario. All input is appreciated. Thanks.

 

[bastarddsm]

That hole isn't a blind hole it goes into a oil passage. You need to use a stud with a short thread

 

[97blkgst]

No I understand that it is not a blind hole and that it is an oil passage. I am saying if I helicoil the hole do I need to be concerned about the metal shavings getting into the oil system from that passage?

 

[serviceguy]

Yes, I would be concerned. You can probably read somewhere to just put a rag or shop paper towel in the oil passage and thread away but you would take a big chance if you ask me. If the thread is not stripped you don't need to helicoil (or time-sert, which I think is way better but expensive). The stud shoulder should stop it from going further into the head. Any chance you flipped the stud so that the longest threaded section went in instead of the shorter one (as it should)?

.......................................................MANIFOLD SIDE

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HEAD SIDE..............................................................

 

[97blkgst]

Yes, I would be concerned. You can probably read somewhere to just put a rag or shop paper towel in the oil passage and thread away but you would take a big chance if you ask me. If the thread is not stripped you don't need to helicoil (or time-sert, which I think is way better but expensive). The stud shoulder should stop it from going further into the head. Any chance you flipped the stud so that the longest threaded section went in instead of the shorter one (as it should)?

.......................................................MANIFOLD SIDE

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HEAD SIDE..............................................................

Yeah that's what it is. I threaded the wrong side in the head. I just referenced how the rest of them looked and used that as my guide. I guess when the previous owner did the head gasket they installed them improperly which lead to me doing the same thing. Well I appreciate the info. Thanks

 

[gst-turbo]

Maybe you can try at put some washers

 

[Chumpaumpalumpa]

It's advisable to use some RTV on that stud to keep oil from leaking onto the manifold

 

[GST Jeremy]

+1 on the rtv

 

[97blkgst]

It's advisable to use some RTV on that stud to keep oil from leaking into the manifold

Oh I definitely plan on using some rtv when I install as it was leaking oil when I pulled the old stud out. But appreciate the help!

 

[serviceguy]

I would not use any rtv there. You may want to use some high temp anti-seize though (the one containing nickel, not the regular one). Same as the other studs and bolts on the exhaust manifold if you want to prevent them from seizing and have to helicoil (or time-sert) them in the future.

 

[Chumpaumpalumpa]

I would not use any rtv there. You may want to use some high temp anti-seize though (the one containing nickel, not the regular one). Same as the other studs and bolts on the exhaust manifold if you want to prevent them from seizing and have to helicoil (or time-sert) them in the future.

Time-Sert always Time-Sert.

 

[97blkgst]

I would not use any rtv there. You may want to use some high temp anti-seize though (the one containing nickel, not the regular one). Same as the other studs and bolts on the exhaust manifold if you want to prevent them from seizing and have to helicoil (or time-sert) them in the future.

Okay so don't use rtv. I was already using nickel based anti seize for the other studs for the same reason you stated so I don't have broken studs in future. Was only going to use rtv to stop the small amount of oil leaking from that studs but we'll see if the new stud and anti seize will seal it up.

 

[Chumpaumpalumpa]

I would not use any rtv there. You may want to use some high temp anti-seize though (the one containing nickel, not the regular one). Same as the other studs and bolts on the exhaust manifold if you want to prevent them from seizing and have to helicoil (or time-sert) them in the future.

I've never used anti-seize on THAT stud; other ones I do but not the bottom center. Always RTV and I've never had a problem or a leak. It doesn't get nearly as hot because it's always being doused with oil. RTV Should keep it from rusting or welding itself to the head. I just removed mine after who knows how long of sitting, removed the RTV and I was on my way. A High temp thread sealant is a good alternative to the RTV.

 

[serviceguy]

I don't think there's a leaking problem with that stud normally, once the stud is fully tightened it should seal the hole. That oil galley is also a return passage only subject to gravity if I remember correctly, unless your head and cranckcase are under such high pressure capable of pushing oil through the stud thread I think the main problem to be addressed would be preventing the stud from seizing, especially when using stainless steel ones. It has worked for me so far but I may be mistaken...

 

[Chumpaumpalumpa]

I don't think there's a leaking problem with that stud normally, once the stud is fully tightened it should seal the hole. That oil galley is also a return passage only subject to gravity if I remember correctly, unless your head and cranckcase are under such high pressure capable of pushing oil through the stud thread I think the main problem to be addressed would be preventing the stud from seizing, especially when using stainless steel ones. It has worked for me so far but I may be mistaken...

The first time I pulled them on mine and a friends car, they were leaking through that hole. Enough to leave a nice dark trail behind it. Some people like yourself can get away with not using a sealant of some sort but I like to be safe so I don't have to do it again later. After using some RTV, both our cars were leak free from there. You just need half a pea and wipe it into the threads and thread it in. Don't go crazy. Anti-seize is a good idea on all the other ones though.