Ceramic Headers Vs. Stainless Steelby Richard Rowe
Material science is constantly evolving, but it seems never fast enough to keep up with the demands of speed freaks everywhere. Ceramic coating is a relative newcomer to the aftermarket scene, and many have rushed to either buy precoated headers or have their existing headers coated. But the process isn't cheap, and some have said it isn't worth it, but that depends on your priorities.
The old-school approach to building headers has traditionally been to make them out of mild steel and perhaps coat them with chrome for appearance and corrosion resistance. But chrome has a way of flaking off when the substrate metal expands and contracts at nearly 1,000 degrees, especially when it's cheaply applied. Stainless headers get around this problem by using a material that doesn't corrode in the first place. Ceramic coatings take that a step further. These coatings, made of aluminum powder mixed with ceramic dust, are sprayed onto the header as a powder and then baked on in an oven. This forms a hard, impermeable barrier that doesn't corrode.
Normally, precoated ceramic headers cost about twice as much as their uncoated counterparts, but that isn't always true. Stainless headers cost significantly more than mild-steel headers, closing the price gap between them and ceramic-coated, mild-steel headers. Narrowing the gap even further are those who opt to have their headers coated at a local shop. This can drop the price of the coating by about a quarter to a third, depending on where you go and what it charges. It's even less if you buy the powder and do it yourself. So a good set of stainless headers could end up costing about the same or more than a set of DIY or locally coated mild-steel ceramic-coated headers.
Neither stainless or ceramic materials corrode, so you'll never have to worry about rust. But stainless steel does discolor when the header gets hot, and ceramic doesn't. Ceramic headers can maintain their out-of-the-box, chrome-like appearance for many years, and the smooth surface makes them easy to clean. Stainless-steel headers can also be quite shiny when they're polished, but they do discolor to a hot-metal shade of tawny gold, fading to cobalt blue around the hottest areas. Some people really like the racy look, though, going so far as to polish the header again after running it to bring out the shine and color. So beauty is in the eye of the beholder as far as choosing by appearance goes.
Beauty may be subjective, but ceramic's vastly superior ability to control heat isn't. Ceramic material is a fantastic heat insulator -- that's why disc brakes on racing cars and tiles on the leading edges of the space shuttle's wings and nose use ceramic. The difference in heat radiation can be profound, especially in the confines of an engine compartment. "Popular Hot Rodding Magazine" found that during testing, its set of stainless headers ran at a scorching 870 degrees Fahrenheit. A set of ceramic headers on the same engine registered a mere 258 degrees. Barely hot enough to boil water. The ceramic headers dropped to 195 degrees within a minute of shutting the engine down; after that same minute, the stainless headers were still 520 degrees. So, for a cool engine bay, ceramic beats stainless by a long, long shot.
In the same PHR header test, the magazine found that the ceramic coating made almost no difference whatsoever in power output on that engine, but that was just on that particular engine. In any case, ceramic is never going to hurt power. In terms of durability and corrosion resistance, stainless wins over mild-steel headers that are coated only externally with ceramic. Headers coated inside and out with ceramic should last just this side of forever, or at least comparable to stainless.
Which one of these you choose comes down to your priorities. If you can find a set of stainless headers cheap and you don't care about 850-degree pipes inches away from your brake master cylinder, rubber lines, spark plug wires and firewall, and you don't mind the discoloration, then stainless pipes are perfectly fine. All things considered, though, especially when you factor in the possibly negligible price difference between new stainless and DIY ceramic, it's hard to make a case not to use coated headers. Your engine will run cooler, your cooling system will work better and everything under your hood will last longer. But, if you absolutely cannot stand the idea of using mild steel and running the risk of them rotting from the inside out, there's nothing to stop you from ceramic coating a set of stainless headers. Then, you could have the best of all worlds with the compromises of none.
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