Exhaust Barrel Nuts 4 Thin Flange Heat Exchangers

[MotoSook]

OK Gang. I've been looking for the last hour for a reference/thread (yes, I know how to use the search button ) to the long barrel nuts that one might use with thin flanged SSI's or early heat exchangers when installing them to an engine that had the thick flange HE's.

I recall there was a thread where someone (I think it was Brad something) posted a link to a supplier that sold the deep barrel nuts.

I printed out the catalog page for those nuts, and I have no idea where I put it, probably in with the thousand or so stuff I print out for later reference (but can never find again!).

HELP!

[RoninLB]

Pelican should sell them... they also have the copper plated nuts.

[MotoSook]

The barels nuts Pelican has are for stock installs..

the ones I'm talking about look like these, but they are longer... to make up for reduced flange thickness..




Or do I need to search the Pelican catalog again?

[fintstone]

Probably looking for Brad Roberts of SSI. He posts a lot on the 914 pages. He is a wealth of info...try a pm.
Stoney

[RoninLB]

I searched around McMaster-Carr, pelican, etc. and did Not find long barrel nuts.

I use SS M8/13mm and a cheap filed 1/4in socket. Maybe the 12mm box copper nuts with a deep flex socket. KTL/ Kevin posted that the copper is soft so I guess it's somewhat full copper. I have a bunch if you want me to experiment.

The routine seems to be a stack of washers if you want to use the short barrel nuts.. party hearty.

[ChrisBennet]

The nut you want is called a "coupling nut". I looked on MSC and found some. Metric Coupling Nuts


Just go to MSC, McMasterCarr, etc and do a search on coupling nuts.
-Chris

[Ray 911s]

Coupling nuts are threaded all the way through. You would also have to change your exhaust studs to use these - the stockers are not completely threaded.

[ChrisBennet]

Originally posted by Ray 911s
Coupling nuts are threaded all the way through. You would also have to change your exhaust studs to use these - the stockers are not completely threaded.

Coupling nuts would be hard to install in place of the barrel nuts but I don't see how they would require different studs.
If you can't find these long barrel nuts, take some normal ones, drill out the threads and then weld them to coupling nuts.
-Chris

[Jim Sims]

Coupling nuts are not a usable substitute; the have no internal wrenching feature and there is not room to get a socket into the heat exchanger access tubes. One would have to resort to the "SSI bent wrench" method (if this is even possible) for all the studs that are accessed through the tubes. Neither coupling nuts nor a taller barrel nut will work if there is not adequate thread length on the lower end of the stud. One may have to make a spacer bushing or use a stack of washers. Jim

[Gunter]

Jim said it.

[William Miller]

Why not replace the studs? Afraid. Maybe for good reason.
I was in the opposite situation, thin flange and long studs. This was from the PO. They stacked washers. I was fortunate enought to be able to buy SSI w/thick flanges. I did however replace at least a few studs. One problem was that some of the previous studs had no threads near the base of the thin flange so there was no option except replace or use washers.

[Vipergrün]

Souk, the "Brad" is here Use the coupling nuts, they work great!
Caveat, I did have to bend a wrench to get these to work. Big deal.....

[island911]

Originally posted by RoninLB
. . .
The routine seems to be a stack of washers if you want to use the short barrel nuts.. party hearty.

2nd

[Randy Webb]

It shouldn't be too hard to remove the studs. If too fearful of snapping one, then I would use grease or glue to stick the washer stack or bushing to the regular nut.

But first I would call or fax SSI - it would be great if a longer nut was made.

[emcon5]

Originally posted by RoninLB
The routine seems to be a stack of washers if you want to use the short barrel nuts.. party hearty.

3rd. I used some SAE nuts slightly larger than the studs as spacers, with the stock barrel nuts. Hose everything down with anti-sieze, and it is a piece of cake to swap it out every 2 years.

Tom

[MotoSook]

O.K! So spacers is the way to go. No problem, I can machine a set easy enough.

Just one thought, why doesn't everyone replace their studs with stainless studs, or something new when they have their headers off? Esp. the guys that have their engine on a stand.....

[RoninLB]

Originally posted by Souk

, why doesn't everyone replace their studs with stainless studs, or something new when they have their headers off?

I've been using stainless for automotive since '66.. in lew of that i personally feel that there is an acceptable place for SS and an
un-acceptable place. As an exhaust stud is ng imo. As a nut on the stud IF using proper technique and maintence it's perfect.

fwiw, I use nickel anti-seize. I think I can send 2oz for 2 stamps in an envelope..

[MotoSook]

Thanks for the offer Ron. I think I have some in the garage.

OK..so why is a stainless steel stud not suitable for an exhaust stud?

[RoninLB]

Originally posted by Souk

OK..so why is a stainless steel stud not suitable for an exhaust stud?

it'll loosen without lock tite.. and I wouldn't trust lock tite to hold them for the long term. and it's really not necessary to take a chance if new studs are never seize maintained.. besides the heat expansion sucks, I believe.

I bet Jim Sims could give you a better answer, either a yes or no.

[MotoSook]

I figured it would have to do something with the different expansion coefficients. Makes sense to me. I could have sworn that there was someone using ss studs or maybe it was just the nuts...

So now someone tell me about the metallurgy of the stock studs