Can I expect an increase, or decrease, of heat in the '73's car's interior when switching from the stock ram-horn exhaust manifolds to the header-type? Specifically, Blackjack Alumicoat on a 383 with a side exhaust system.

Thanks in advance.
Steve

 

with side exhaust, less heat. You have the firewall/under body shields still on the car?

 

I went from stock manifolds and stock exhaust to ceramic coated headers with side pipes.
Significant reduction in heat. Never an issue even on the hottest days with A/C. Get the heat shields if you want to keep the skin on your legs though.

 

I just picked up TODAY my XS power Stainless steel 1 3/4 inch headers from being ceramic coating just for the heat issue you bring up...came out great...will be a bit before I can run the engine with them on since the ceramic process requires 500 degree baking and THEN 5 days of air curing BEFORE I can run the engine...installing them tomorrow but no engine running until next weekend...Traveling for work.

 

Photobucket ain't workin for me today for some reason. I can't show what I think you folks are referring to when "heat shield" was mentioned.

But it's nice to know that, in general, things inside the car get cooler with Headers and Side Pipes.

Thanks Gents.
Steve

 

These are the heat shields I was referring to.

http://www.steelshields.com/

There are cheaper options available but I would use some form of shield to protect your skin when entering/exiting the car.

I have Dean's shields and I can put my hand directly on them after driving for any length of time. They are of a high quality stainless. A magnet will not stick to them.

There was a heat shield under the car where the catalytic converter was on the stock system that I removed. No other shields under the car are in place.

 

You folks have mentioned ceramic coated headers. What if they are not ceramic coated? My understanding is that cast iron withstands heat better than uncoated steel tubing. More info????

 

Up to about 10 years ago I ran the stock OEM exhaust manifolds since my prior experience with LTH headers on my 73 Nova SS as kid in the late 70's early 80's was that they were noisy (engine metallic sounds through primaries and collector), engine and road clearance issues, AND threw a ton of heat on warm days through the engine, cabin, and from under the car. They also rusted....a went through a replacement warranty set back then. The OEM manifolds on my C3's and most cars are thick heavy cast iron steel with MUCH less surface area than LTH's ..for all these deisgn features, the issues mentioned above are minimized. Cast iron retains the heat very well inside the manifold versus allowing it to emminate outward from the cast iron. They still are hot but less so..

The shorties I had on my 78 and on my 94 Mustang GT both ceramic coated do not generate any more heat than the OEM exhaust manifolds (verified with infrared temps on the mustang). The Ford tubular exhaust OEM manifolds are uncoated versus the BBK ceramic coated shorties and the OEM's generate MORE heat. I love shorties since there are no engine and road clearances issues as well. With the 78 L-82 355 engine with AFR heads and roller cam, I just could not ignore that I am leaving significant HP on the Table running a Shorty Header with 1 5/8 short primaries and 2 inch collector....

I had the XS Power Stainless Steel (stainless will throw a TON of heat uncoated but won't rust LOL)) 1 3/4 inch LTH headers coated BOTH inside and outside since I am anticipating just slightly more heat than with the ceramic coated Shorties, primarily since these headers are serious LTH headers with lots of surface area...can't get around physics. They came out superb....

 

I believe these are what you were referring too Mel, correct?



Steve

 

Mine are ones I fabricated. Please, don't laugh.





The Headers.



The plumbing.



Just concerned about the heat.
Steve

 

Appreciate the info sir. Thanks much!
Steve

 

Those heat shields look really good to me. On deans there is a length of stove door seal like material to isolate the shields from the pipes. You may consider that on your standoffs so heat is not transferred to the shields via the stand off. Clever design by the way.

I can say in my experience that the stock manifolds created more heat than my coated side pipe headers do. I imagine that uncoated long tube headers would radiate more heat than the stock manifolds just due to the increase in surface area. The amount of heat radiating off of coated tubes may vary with how easily the exhaust can get out. In a side pipe arrangement there is little back pressure.

 

I noticed that in your set up you have a long curved 3"? tube to get to the side pipe. That is going to radiate quite a lot of heat if it remains uncoated. You could try it out and see how it goes. That tube will be pretty close to the floor though so could warm up your feet a bit.

 

I have Hedmann coated LT`s on mine 468 BB, much cooler underhood temp!

 

Yes. It was hard to see. I think the stuff was labeled Header Wrap. Was in a 2" wide roll, which I had to cut to a narrow width in order to fit the band-clamp.



Steve

 

Yeah..... I think (I KNOW) the rest is beyond me. I'll see what the muffler shop has for a coating, and I'll have him do the cutting, bending, fitting and hanging of those dudes.

Need to finish the painting first.



Too much, too fast.
Steve

 

Nice to know!

Steve

 

Not to be too sciencey here but the heat emission between cast iron exhaust manifolds and steel headers is all about surface area. A cast iron surface (unless polished--ain't gonna stay that way for an exhaust manifold) is a much better emitter of heat than steel as used in headers. This is ALL about emissivity--the simultaneous and equal ability of a material to both accept and transmit heat.

As steel headers rust on the outside their emissivity increases to eventually become greater than cast iron.

 

Now I see WHY stoves were built out of cast iron.
The stock Ram-Horn manifolds absorb and radiate the heat from and away the cylinder head/block area very efficiently for a cooler operating engine.

Thanks Mike.

Steve