Headers and heat issues?
 

I'm about to install headers on my '79 SC. As I am in FLA, I will not be using the heater function. However, after reading a few threads here, it seems that stock heat exchangers may help "cool" the engine in some circumstances.

Are there any issues, regarding heat/overheating, when installing headers?

Also, can Porsche headers be ceramic coated (i.e. "JetHot")?

You can Jet coat them both inside and outside. I had it done.
However, I cannot attest to long term effects on increase of engine temp because the shrouding over the pipes as on heat exchangers should reduce heat convection and radiation effects quite a bit (50%). Though with the increased airflow around the pipes when driving probably will not be cause for concern.

Plenty of guys who race their air-cooled 911s use headers and place block off plates on the shroud where the air duct(s) were. Of course many of them also run additional external oil cooling, but I think you'll be OK.

here's the discussion regarding blocking off the heat boxes, with a lot of insight from Grady

http://forums.pelicanparts.com/porsche-911-technical-forum/288020-question-mfi-people-out-there.html?highlight=MFI

you did not say if your headers have heater boxes or not.
but it makes good sense to direct at least some air down there to reduce heat buiild up and save the welds from popping.
consider resorting to the 30mm block off plate mentioned by Grady as being the factory solution.

Bill K

Good reading. However, I plan on removing my heat exchangers.

There are no heater boxes on the headers I'm planning to install. How do I subsitute in order to get hot air to the t-stat?

this is only a concern if you are running MFI

Re: Headers and heat issues?
 

Did the same thing you are contemplating. As I am in SoCal, I didn't feel the need to have heat either. The lower end headers are made from mild steel and are an excellent candidate for ceramic coating. I had my George Narbel headers done inside & out for $100 (good guy price, expect to pay more):

http://forums.pelicanparts.com/uploa...1155608991.jpg

Lots of things were modified at the same time to promote increased cooling for the bigger bore motor that sometimes has to sit in stop and go traffic so I don't have any hard numbers that you can take to the bank. The a/c condensor was removed from the decklid and the a/c compressor and associated bracketry was also removed from the engine. The oil temp NEVER goes above 210°F even in a traffic jam on a 100°F day (and we have lots of them). I have no need for additional oil cooling for street use.

You may also require a block-off piece of tin for the left side of the motor, you can buy a fiberglass version from one of the shops like Getty, MA Shaw, etc or if real lucky pluck one from an RSR motor like I did:

http://forums.pelicanparts.com/uploa...1155609466.jpg

The gist of my long windedness is simply that every little bit helps when trying to cool the motor. In my case, I was able to do it by making these changes without having to resort to adding another oil cooler.

Ralph