Heat exchanger install with Permatex??

Mike Kunz · Mike Kunz's Garage

Can anyone advise whether or not I should be using high-temp Permatex on the copper gaskets when reinstalling the heat exchangers on my '74 2.0? I used Permatex and I now have more "blow-by" than ever! Should these gaskets go in "dry" and if so, how the heck can I keep them up there when raising the exchanger to the cylinder head?

Thanks!

Germain · 06-21-2000, 05:57 AM

Mike, I put mine in dry exhaust sounds good.
You need to hold them in place? Don't you have the .008 diameter hand required to work on a Porsche? Well if not you can always use peanut butter... Someone on this board mentioned this, and damn it worked good. Sorry I can't give credit where its due, but thanks for that advice whoever you were. I used Jiffy Creamy and it was much sticker warm. If you use Peter Pan, your results may very

JP Noonan · 06-21-2000, 03:29 PM

Make sure the old gaskets are rmoved, they can get carboned up or melt into the head. Use a big mill file to even off both exhaust flanges at the same time. I use a spray on copper coating, gasket dressing. Permatex and other companies make it, the silicon stuff is too thick and ends up melting off.

Don't over tighten the exh studs at room temp because these engine expand so much with heat the extra torque can pull them out at temp. Also make sure all the exh studs are there and that you use a muffler hanger.

Jim Smolka · 06-21-2000, 03:35 PM

I have used axle grease to hold the copper gaskets. Another item, sometimes the studs are too long and though the nut bottoms out, it is due to the lack of threads and not the torque cause by compressing the gasket. I have used washers before.

Also, be sure to use anti sieze on all exhaust nuts.

IMHO

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Smoke Daddy

Mike Kunz · Mike Kunz's Garage

Thanks, Guys....got some good info. here and will crawl back under the car this weekend to get this solved!

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Real Porsches have their engines not only in the back, but in the middle, too!

JP Noonan · 06-22-2000, 08:44 AM

Porsches don't leak oil. They just mark their spot.

Mike Kunz · Mike Kunz's Garage

OK...everything is apart now, cleaned up and ready to go back in....

So, what is the tightening torque for the exhaust nuts? Can't seem to find this in Hayne's or anywhere else. And I assume from the previous post that they should be torqued with the engine warm?

Thanks!