I'm looking for a set of used thin flange SSI exchangers for my 1979 3.0 SC. I know it's a long shot but anyone have a set that they aren't planning on using?

 

I just scored a set used off Craig’s list. 800 Usd if you are interested in price point pm me if you find any as I’d be interested in how you make out

 

Isn’t 79 thin flange ? Or did you have the studs replaced ?

 

Hmm, seems you're right. I had read that 1977 was the changeover year but doing a bit more digging shows that 1979 was the final year of the thin flanges. Guess I need to change my thread title! Or my studs....

 

I have a fair bit of experience with this so you can always Pm me for more info if you like .
getting the old exchangers off the studs without breaking them after 40 years could prove to be a very big challenge, but say you do ..... you will need thin flange exchangers. If you do decide to replace all the studs ( which I do not recommend ) because you really need the engine out on a workbench to do it properly. you can get thick flange exchangers , but there is a caveat. on 80+ on cars there is a recess in the heads that the protrusion from the thick flange SSIs sits in. If you are going to use Thick flange ssis you need to cut off the protrusion from the SSIs so it can go flush against your 79 Heads.

If you post in the air cooled forum under 911 there is more discussion there if you would like technical help.

 

Thanks Ice, I may be in touch!

I ordered a set of new thin-flange SSI's this morning after a sleepless night of trying to convince myself that they are a wise investment... of course that investment also included the two necessary oil lines, new gaskets and all new hardware to mount them with, luckily I already have a beauty muffler left over from my last 911 (1975 S) that wore SSI's. Probably should have kept the exchangers too! Hindsight: 20/20.

While I was under the car measuring the existing stock exhaust flanges, I soaked all the rusty fasteners in ACF50 (Fantastic product, by the way. I've sworn by it since my aviation days.) so they'll hopefully be willing to release their grip when the time comes. I'll likely do it again a couple of more times before the exchangers arrive since I have the time, and the desire to not break any studs.

 

Historically speaking no fluid has done anything to get those nuts off
You need to get the nuts cherry red. Lowe’s sells a great map oxy setup with a pencil tip that works well.
Don’t use too much leverage. If it doesn’t come heat it again.
Got all 12 of mine out. Those who try it without heat usually break 6-11 studs off

It is gonna be tough under the car. I hope you have a lift

 

Nope, just a pair of jack stands and a big piece of cardboard.

 

If I was you I'd pay someone an hours labour to do this for you. Maybe even replace them.

 

yeah this would be a nightmare to try and do what you are attempting with not even a lift.

 

It took me the better part of a day to get mine off with the engine upside down on an engine stand.

 

Seems like a lot of worry for 12 nuts that I can easily see when the car is up on the jacks... what am I missing besides 38 years of corrosion? Yeah, that's a lot of potential heartache but I've pulled scabby 50+ year old engines apart (American engines, granted) and never had an issue with an exhaust (or any other) stud breaking.

Am I really being too naive? You guys are scaring me enough to want to just drop the car off at my fave Porsche Indie shop and pick it up a few hours later with the SSI's installed.

 

They are notorious for snapping. A guy on pelican just tried with fluid. Snapped 11 of 12

Just missed a perfect record 😉

 

And off to the professionals I go!

 

Did you score a set ???