Exchanger replacement help:

[rickeolis]

I am going to have my exchangers rebuilt, and I have looked at what I would need to do this.

Does anyone know what the size of the 'allen head' bolt tool I need to remove these is? Also any help on doing this job on my 1969 911T would be appreciated much!

There is some rust down there...

[Superman]

I'm going to direct you to do a Search. There is a lot of material on this Board related to your question. Rust can be a real problem because it can cause exhauts studs to break off. If this happens, you will need professional help. This may be a job for a pro.

[jriera]

Rick, that will be the extra-long 8mm allen key, and also you will need a 13mm universal join for the other nuts... saying that there is some rust in there is a large under-statement...

There have been several (very good) articles on how to do a proper drop of the exchangers (including rust-eater, heat, etc.) do a search under heat exchangers.

Buy a large bag of patience.. you will need it if you don't want to break many studs... ask me how do I know..

Good luck.

[T Bird]

Rick
The 6 barrel nuts are removed with an 8 MM inhex tool. The 6 other regular nuts require a 13 MM socket for removal.

Check the tech articles- there is an article on SSI installation that discusses the removal of these nuts in depth. Also, search the archives. This topic has been discussed many, many times in the past.

Good luck.

[Doug Zielke]

Yasss....look for the threads titled 'SSI Clinic'.
Probably, the most important thing you need to know about removing the exchangers, is you will require a Oxy-Ace (not a wimpy propane) torch to heat the fasteners. We're talkin' red hot, baby!
Most of the time, penetrating oils will just not budge the rusted parts, and you'll risk breaking the studs. But with a torch, the job is almost a (dare I say it) snap.

[rickeolis]

Yeah, I have been doing searches, thanks. I am indeed very worried about breaking the studs.

jriera- You are so right, some rust is quite an understatment. There's a sh*%load of rust under there! So what do you do when you break a stud? Take the whole thing to a shop?

I tried to get the 17mm nut and bolt off at the muffler joint since I had the access and tools, and even when using a good 6 sided socket and a cheater bar, all I managed to do was to round off the nut. I stopped before trying to hurt anything else. I have sprayed a rust breaking lubercant into these joints.

So does it look like maybe I might consider taking the car to a shop and paying them to just remove the exchangers? Would someone want that kind of liability?

[jriera]

Rick, I had to saw the exchanger to get the muffler out (the 17mm nuts/bolts you are referring to). I broke 3 studs in total (after doing all the heat, rust-eater, etc.) but I manage to get the old exchangers off and install the new SSI's.

Obviously with 3 broken studs I had leaks and the car sound like a Harley (nothing wrong with that) but the Texas tech.inspection do not like exhaust leaks.. so after much trying to remove and replace the broken studs I decided to bring the car to my usual shop (Ed Mayo) where they replaced all 12 studs with new ones.

If I will have to do it again (with another set of original exchangers) probably I will send it to the shop directly, it was fun, I learned how to do (and not to do) a couple of things and give me the chance to clean prety good the 'belly' of my car.

Any Porsche shop will be glad to do that job for you (for a price of course), expect to pay $300 to $500 (depending on how many broken studs and if they have to be drilled, timecert, retap, etc.) for a complete removal/reinstall.

Hope this helps.

[rickeolis]

Well, I just read the posts about the SSI class. After I stopped laughing about the pic with the blue towel.

I see where the heating of the studs seems to be the key trick.

SuperMan: " JW removed one with the torch alone!" What do you mean?!?!?

jriera: Thanks for the sizes for the tools! Wish me luck...

Tyson and Walker: Wish I lived up there!

All the responders: Thanks

[82SC]

check the tech article section of this website...

there was a thread a while back about some corrections a guy found in my article as well

MJ

[Superman]

Rickeolis, John got the nut extremely hot, the blasted it with that little lever on the oxy/acetylene thing. I think it is a small lever that allows a sharp blast of oxygen. Blew that nut right off! This is why the pros are not afraid of nuts when they have an oxy/acetylene torch nearby. With this tool you can just get something so hot it's not even a solid any more. Takes about 30 seconds. Turns the nut into a kind of bright orange jello thing. Then when it lays on the ground for a minute or two, it looks cool but it's not. Have a beer before you touch any of those nuts.

John also has a fixture he can bolt onto the exhaust port that centers a drilling tool so that he can drill out the sheared-off exhaust studs without damaging the soft aluminum heads. Without one of these centering fixtures, it would be very difficult and time-consuming to do the (drilling) job by hand. Without damaging the head, I mean.

[ChrisBennet]

You may find that those nuts are 12mm. The ones on my Carrera were.
-Chris

[jriera]

Rickeolis.. good luck!!

.. and Chris Bennet is correct (as usual) you may need the 12mm universal join and deep-socket wrenches just in case someone has already changed the nuts (like I did for the new exchanger).

Keep us posted.