Naive question: Is this a dreaded thermal reactor?
 

Wondering if this piece is the dreaded thermal reactors from the mid-year cars, or is it just an early heat exchanger? I have some confusion about the thermal reactors and what they actually look like. Thanks. Kirk

http://forums.pelicanparts.com/uploa...1171480778.jpg

Nope, just a heat exchanger.

Kurt - Thanks! So this means I don't have to get rid of them necessarily in favor of the expensive SSI's I keep reading about? It was my understanding that a 1976 would have them, but the engine was already out of the car when I bought it, so I guess I don't know what thermal reactors look like.

Kirk

Kirk........these are the dreaded thermal reactors.

Sean
http://forums.pelicanparts.com/uploa...1171483290.jpg

Kirk,

Your question is not so naive. It took me a little time to figure out all the exhaust stuff also - there just isn't a good picture where everything is laid out and identified. Here is a picture of someone selling thermo reactors (the round cylinders) and heat exchangers.

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/321810-wts-1976-parts.html

The following is what you want - similar to an SSI set-up, except these came stock in 1974 and earlier:

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/330091-fs-complete-1977-exhaust-system.html

With your old system, the right side exhaust exits to the front of the car, goes around the engine, combines with the left side exhaust, then goes to the muffler. With the SSI or 74 and earlier, the exhaust exits the cylinders and goes straight back to the muffler. Much shorter distance, and less heat soaked into your engine - especially when sitting in traffic or at stop lights. SSI are a good idea - high quality and long lasting. Buying an older stock system is cheaper, but more of gamble in quality due to rust or road rash over the years. JMHO.

Thanks Rex and Sean M. I now have a much better understanding of what I am dealing with. That said, the motor I have is questionable and perhaps begging of a rebuild, though I am not inclined to spend all that a 2.7 demands. The car/engine only has 35 K miles, but the car had been stored for a long time. I think my best bet is to use the exhausts I currently have to find out more how this engine will run, then if I feel halfway satisfied that the project deserves more money, I will probably look to purchase a used set similar to the ones Rex provides a link to. Thanks all! Kirk