What material are heat exchangers made of?
 

Were heat exchangers ever made from stainless steel? If so, when did Porsche start making them from stainless?

The earliest quotation that I can remember was sometime after 1974 the replacement heat exchangers were made of Stainless steel. This meaning that the outside sheet metal was stainless. My interest at the time was the "early" style heat exchanger ment as a replacement for '74 and earlier cars.

I hope this helps.

David Duffield

Yes that helps, thank you. But, you say REPLACEMENT heat exchangers. What about original as delivered from the factory? The reason I am asking is that I am looking at purchasing a used original one, and am wondering if it would be stainless.

If you go back before the early '70s heat exchangers were made of normal steel and rusted quickly. Given the potential for CO poisening early efforts were to make the outer parts rust before the inner, hence the exhaust tubes themselves were the first to be made of ss. Eventually by the mid '70s the entire heat exchanger both inner and outer parts was ss, w/ a higher quality ss still used on the inner portions.

If that's true why is it the heat exchanger on the 81 on the left side is rusted away from the outer shell?
The coupe(gone to the new owner) was a 79 and it's rusted also..?
Am I misunderstanding something?

They designed the outer parts to rust first for safety.

Thanks guys! That is exactly what I needed to know. My left side is rusted away too, so I don't get much heat from that one. My right side is in perfect shape though from an oil leak at the oil return tube. Maybe Porsche designed their engines to leak at a certain mileage so that it would protect the heat exchangers.

Looking at my heat exchangers on my 78 SC Targa I can only say it is probably coated steel which is probably galvanize. However, I may be wrong. If you take a magnet to them that will tell the story.

Steve

"A Porsche does more then just go fast in a straight line"