Question: Installing SSI thin flange

[Tidybuoy]

Got a question. I removed my SSI's last night, mine are the thin flange type. My setup had large 3/4inch copper spacers between the flange and the nut but I don't see these in the Pelican catalog.

I haven't checked yet but I don't think I can do with out the spacers as there might be a non-threaded section on the exhaust studs, meaning the nut will only screw on so far. I don't want to reuse the old spacers as some of them were slightly crushed and really clamped onto the stud. I had to use pliers to grab and unscrew from the exhaust studs.

Do you think the prior owner used the spacers because the exhaust studs are for the thick flange SSI's and therefore are longer? Do you think I should replace all my exhaust studs and use shorter which would eliminate the need for the spacers? Is it possible that this setup was contributing to my exhaust leak(s)?

Any advice would be greatly appreciated.

Vern

[72911]

Why not use a "tube" type spacer AFTER you put your gasket and header on? The stack up would be gasket, header flange (thin), tube spacer, lock nut. A spacer might also be called a stand-off spacer and it covers up the non-threaded section of the stud.

[Tidybuoy]

I was thinking that I should replace the longer studs with shorter as I think the spacers are causing the nuts to not be as torqued as tight as they should.

[john walker's workshop]

good luck with that. the studs are tough to remove. i try to let sleeping dogs lie.

[The cap'n]

Agreed. Last one I did required 12 Helicoils and a TON of drilling, for which you need a fixture. You may not want to do that, especially if you don't have a lift, the fixture, and a bag of drill bits.

The Cap'n

[72911]

Stainless steel spacers are available at Grainger in a variety of sizes and lengths. Torque should hold better using SS compared to the copper spacers you now have (on the head side).

[fred cook]

I had to change the exhaust studs on my Carrera heads. I used a propane torch with the heat applied in the exhaust port next to the stud. All of them came out intact! In the past, I was not so lucky and wound up having to drill a couple of broken ones out. If it was my engine, I would change out the studs for a set that are the correct length. Otherwise, you might be spending a lot of time keeping the nuts snugged up and once the heat exchangers are installed, some are really hard to get a wrench on!