Any thoughts on cleaning the insides of heat exchangers.

I acquired a used set, cleaned up the outsides, and hooked them up. Last night I put the muffler on and let the car run for a few minutes (a recent development that I am quite thrilled about). A few minutes later it started smoking like a chimney. A quick peek underneath found that the smoke was pouring out of the heat exchangers.

At least it got all of the mosquitoes out of the garage.

Thanks

What did you use to clean them with?

Get em powder coated. That'll clean em up. Then they won't rust either.

I used a combination of brake cleaner and elbow grease for the outside, nothing for the inside. Any particularly good solvents, or just let it burn off? They're the SS variety so rust shouldn't be an issue.

I let mine just burn off, but I suppose you could get a large bottle brush (from the Dollar Store), some coathanger wire, and degreaser or oven cleaner, and go to town.

-Rusty

That sounds like fun, but I probably should make sure its taken care of before I hook the heat up. I might be a little distracting for smoke to start pouring out of the vents while driving down the road (or even sitting in the staging line at an autocross, right jdogg).

thanks guys

simple green is good for baked on oil residue. lay down some cardboard and kitty litter to soak it up.


powder coat/jet snot is a good long term solution. there is a jet hot coated 930 exhaust on pelican 911 forum . search for the thread. they are sweeeeeeeeettttt.

Easy off oven cleaner...


B

Castrol SuperClean. I've never seen anything that cleans grease like this stuff. Wear gloves! Washes off with water.

Ummmmm! lets see...

Get them hot tanked at a local automotive machine shop.

Ignorant question.

What is "hot tanked" and how much$?

"Hot tanking" is the process of taking a part and dunking it in a really evil cleaning solution that is heated.

As I recall, the solution used is really caustic and really does Bad Things to aluminum. SS should be fine, though.

There is also "cold tanking", which uses other chemicals (not so aluminum-unfriendly, I think?) and no heat.

The $$$ depends wholly upon where you take the part. Most machine shops have access to either or both.

--DD

I remember a guy on another mailing list a few months back who had just gotten his 356 case back from his mechanic, who was going to help him rebuild it. It was all shiny and new again after pulling it out of the hot tank, but he just couldn't figure out why the bearing seats wouldn't fit anymore.

Nobody was happy giving him the bad news. . .

(IIRC, the cleaning solution is called "Caustic Soda" - I'm guessing it's something like Lye?)

A good shop should know if something is mag or aluminum right away. You can see it (the aluminum) in the solution, looks like your pouring silver paint into it.

Hot tanking is for steel parts only. Price will depend on the shop and how long the parts have to be tanked for, my guess $25 to $50 for the pair.

Oh, if you put an aluminum engine case in a hot tank over-night, all you will have in the morning is a bunch of studs.
That mechanic was a total moron.