Heat exchanger removal, SWEET VICTORY!!

[Nathans_Dad]

I soaked my nuts for two weeks in PB Blaster and then a couple days in Kroil which I ordered from Amazon (inside jokes with my wife all week about soaking nuts).

Got under the car this morning and started turning wrenches. One hour later the heat exchangers are down!! There was only one nut that was a little tough to get off (the forward most driver's side nut), mostly I think because it was harder to get a good grip with my 13 mm wobble socket.

Everything came off pretty easily and here's the best part, NO BROKEN STUDS!!!

I bought a small torch to use in case any were really stuck and didn't end up needing it.

I think I should go to Vegas now while my luck is hot.

Here's the money shots!



Driver's side:



Passenger side:



Now on to the oil return tubes! The exchangers are going off to a ceramic coater to get blasted and coated. I'm probably going to have to cut the nuts off of that connector pipe, they look pretty corroded.

[Elombard]

I am so impressed, I wonder if yours have been off before? my motor looks similar age wise and not even close to success.

Good job. You should probably go ahead and buy $3k worth of stainless exhaust beauty to put in there now :-)

[Nathans_Dad]

Yeah I suspect the exhaust has been off before too. I noticed the fasteners on the connector pipe between the exchangers are VERY corroded while the fasteners for the other connections and the exhaust studs themselves were in better shape. Still rusted, but not as bad.

Plan right now is to get the stock exchangers cleaned, media blasted and ceramic coated. Unfortunately the budget won't allow stainless steel bling just yet, maybe someday!

[zippy_gg]

You are very lucky indeed.
So far I only removed the cat and muffler, and spent upward of an hour on some of the nuts with a dremel when the cutting wheel wouldn't fit.
The nuts and bolts were rust-welded and the heads rounded off as the metal had been eaten away by corrosion.
I haven't attacked the exchangers yet...

[Nathans_Dad]

Here's a question, what's the name of that connector pipe that is still attached to my passenger side exchanger? It's got a few nicks and dents and is pretty rusted, I might just order a new one if they aren't that expensive.

[blucille]

I just did the same on my '79 sc, lots of presoaking with Kroil, and in the 210,000 miles, the motor had been apart at least once.

Did the same task on my 3.0 hotrod motor in the '73.

Neither had broken studs, both had been apart, long ago.

Tried to do this on a '72 I had with 3.0 and had 6 or 8 broken studs, some flush with the head, some not, all were a bear to get out....I get the feeling that motor had never been apart.

Here's my question, why are you putting these heat exchangers back on....you'll gain a lot of power and an infinite choice of mufflers if you backdate the heat exchangers, and eliminate the cross over pipe. I'd conservatively estimate an easy 10-20hp, and I'm sure you can find used heat exchangers compatible with your motor (thin flange) for a couple hundred bucks.

[911dean]

Great job! Hope to remove mine sometime.

I first need to save for an exhaust system.

Dean

[Nathans_Dad]

Originally Posted by sonett43

I just did the same on my '79 sc, lots of presoaking with Kroil, and in the 210,000 miles, the motor had been apart at least once.

Did the same task on my 3.0 hotrod motor in the '73.

Neither had broken studs, both had been apart, long ago.

Tried to do this on a '72 I had with 3.0 and had 6 or 8 broken studs, some flush with the head, some not, all were a bear to get out....I get the feeling that motor had never been apart.

Here's my question, why are you putting these heat exchangers back on....you'll gain a lot of power and an infinite choice of mufflers if you backdate the heat exchangers, and eliminate the cross over pipe. I'd conservatively estimate an easy 10-20hp, and I'm sure you can find used heat exchangers compatible with your motor (thin flange) for a couple hundred bucks.

Well, that's an interesting option, I was under the impression my options were SSI or stock. SSI exchangers are pretty pricey so I was planning on continuing to use the stock ones.

Would backdating be a better option and would I have to drop the engine to backdate the heat?

[blucille]

No need to drop the motor. You've done the hard work. A couple of oil lines would need to be swapped, probably, you'd have to find a muffler you like, but all the bits are out there used.

[zippy_gg]

Originally Posted by Nathans_Dad

Here's a question, what's the name of that connector pipe that is still attached to my passenger side exchanger? It's got a few nicks and dents and is pretty rusted, I might just order a new one if they aren't that expensive.

That is the crossover pipe and it isn't cheap at $235 + shipping and taxes if you are in CA. Add a new gasket and fasteners and you are in the $300 range.
Porsche 911 & Carrera Exhaust Pipes - Page 4

[stuntmangb]

Interesting on your car their are 6 studs per heat exchanger , On my car it has 3 nuts and 3 barrel nut or what you might call them allen screws
Trying to remove heat exchangers on my 1987 911 (111k) at this moment, will fit a stock (standard ) stainless system, Any advise would be helpfull but I live in the Uk (England)

[Ronnie's.930]

Originally Posted by Nathans_Dad

I soaked my nuts for two weeks in PB Blaster and then a couple days in Kroil which I ordered from Amazon (inside jokes with my wife all week about soaking nuts).

So did you develop a rash afterwards?

[Nathans_Dad]

Originally Posted by stuntmangb

Interesting on your car their are 6 studs per heat exchanger , On my car it has 3 nuts and 3 barrel nut or what you might call them allen screws
Trying to remove heat exchangers on my 1987 911 (111k) at this moment, will fit a stock (standard ) stainless system, Any advise would be helpfull but I live in the Uk (England)

Mine is the same, three barrel nuts and three regular hex nuts per side. The barrel nuts come off pretty easily with the long Allen key fitted for a socket they sell at Harbor Freight. I used a 13 mm wobble socket for the hex nuts. Soak in lots of good penetrating oil and see what happens, I got super lucky!

[spsfiend]

Is there a trick to soaking or do you just spray up into the heat exchangers / studs? I am going to be throwing some Rarelyl8 headers on and i keep hearing to soak the nuts. However, gravity is kinda against this so I was wondering if there is a trick to this?

[Nathans_Dad]

Not that I know of. Gravity does work against you. Just get the penetrating oil on there and give the nut a couple good taps with something to help the oil get inside.

[r-mm]

I haven't done this job but wonder - is there clearance for an impact wrench? My $40 harbor freight electric impact wrench is probably MVP on my bare metal (non 911) restoration, especially where stuck fasteners are concerned.

[blucille]

Heat is your friend here....some say to get the fastener glowing red before any attempts are made....if you are concerned about breakage, a mapp torch will get the nuts hot enough to come free without breaking the studs, hopefully.....also, it helps to allow the Kroil or 50-50 ATF/acetone to creep into the stuck fastener.

[peppy]

I think its miller time.

Congratulations!

[cary]

The first time you take it off without breaking something is a tremendous accomplishment.

Putting them back on you'll have all kinds of opinions on what nuts to use.
I use the ones Wayne sells here. Porsche 911 & Carrera Exhaust Pipes - Page 5
Lather them up with copper based anti-seize and your good to go for many years.
I did the same repair with Steve Weiners guidance about 10 years ago.

Don't drive my 911 much. It never needs any work ..............
Its full of Mobil 1 V-Twin and does leak a drop.

[Nathans_Dad]

Another tip I've seen is to crack and retighten the fasteners yearly.