Look at that lead photo. 
Heat management and high performance work hand in hand when it comes to track and autocross cars. Whether it's your tires, your oil, your shocks, or your cooling system, heat has a substantial effect on the way they perform.
While long-tube headers tend to help the engine work a bit more efficiently, creating some additional power, their thin-wall design (relative to exhaust manifolds) and generous routing through the engine bay make them the primary source of radiated heat in most non-turbocharged engine bays. Managing and mitigating this heat has numerous payoffs.
First, cooler underhood temperatures make life easier on other parts—and on the engine in general. All that ambient heat from unprotected headers affects alternators, power steering pumps and oil pumps, and can even melt or seriously compromise wiring that doesn't have enough clearance. And if your engine’s air intake is under the hood as well, you want it ingesting the coolest air possible, which becomes more difficult when the headers are turning your engine bay into a pizza oven.
Second, keeping the heat energy inside the headers makes them more efficient. Radiated heat from the surface of the headers is energy transfer, and that’s energy not staying inside the exhaust path. Yes, this is an incredibly esoteric distinction and probably only demonstrable through complex nerd math, but there’s nothing wrong with maximizing your benefit spectrum.
Finally, a thermal barrier for headers can also be a physical barrier, protecting your headers from damage, corrosion and discoloration. But some thermal barriers do a better job at this than others. Header wrap, for example, is an excellent thermal and physical barrier, but it can hold moisture next to the surface of the header, eventually causing corrosion. Wraps are also quite thick, so they’re not always appropriate for tight engine bays.
For our C5 Corvette, we opted for Swain Tech’s White Lightning ceramic coating. While the company was quick to mention that some people don’t find it the prettiest coating relative to some of the shinier, smoother coatings available, we really dig the textured, industrial look of the ceramic layer bonded to the headers.
That texture isn’t just for looks, either, as the large particles of ceramic material make an exceptional thermal barrier.
One more advantage: Because that material is bonded directly to the headers, there’s no worry about moisture-based corrosion.
Coating a set of V8 headers will cost around $375, although Swain Tech says that price can vary based on condition and required prep.
We performed a quick, nonscientific test to see if we could detect any difference in heat transfer between the uncoated headers and the coated ones. We simply stuck a MAPP gas flame into the collector for a set period of time, then measured surface temperatures at the same place on the collector. To keep our experiment as controlled as possible, we used the same torch and bottle of gas, and tested on days with very similar ambient temperature and humidity.
The results were fairly dramatic. After 2 minutes of heating, the coated header was a full 10 degrees cooler on the surface than the uncoated one. Nearly 8% less heat energy was radiating from the coated header. That’s a significant drop for such a thin coating that won't affect installation in any way like a wrap would.
Like what you're reading? We rely on your financial support. For as little as $3, you can support Grassroots Motorsports by becoming a Patron today.
Look at that lead photo.
I've got Swain on my V8 Miata. I have had trouble with it spalling and coming off and melting on some of the hot spots. It'll be interesting to see how it holds up for your application, especially if this beast goes on track.
I THINK it's aluminum sprayed on to the header and then topcoated with ceramic. That would explain the failure mode if the pipes get hotter than 1200F or so.
It looks great when new and does seem to cut down the heat, but durability and expense will prevent me from trying it again.
It would be interesting to see a similar test with the tube, but seeing where the heat is further down to see how far it projects down the tube.
David S. Wallens said:Look at that lead photo.
Lots of heavy lifting being done there by a stool and a hidden roll of tape :)
Mr_Asa said:It would be interesting to see a similar test with the tube, but seeing where the heat is further down to see how far it projects down the tube.
So, I actually did more tests at different points on the headers, but the readings I was getting were too inconsistent to trust the limited science of my methodology. I think the only way to reliably do that would be to apply four equal heat sources, one to each port. Going with a single source from the bottom up you can't rely on the heat flowing equally into each tube from test to test. At least that's what I was seeing. I think the way I did it there was enough proof-of-concept to make the point without having to bring in a testing lab.
Also, heat makes headers hot. Do not grab. You'd think I would learn.
Interested to see how this holds up compared to Cerakote and other ceramic coatings.
I've had SwainTech coating on my cast iron manifolds and turbo housing since 2005 with great success. The only downside is the beautiful white color doesn't last!
In reply to ZCarBob :
We need more info on this!
Assuming ambient at 80F, I'm figuring more like 30%, based on radiative only.
But then, my heat transfer is a bit rusty.
How does this compare with jet-hot? I am curious on using something like this to finish my exhaust project.
Displaying 1-10 of 12 commentsView all comments on the GRM forums
You'll need to log in to post.
