It used to be that the easiest way to tell a show car or a trailer queen from an actual runner was to look at the headers. Nice clean paint or flawless chrome meant that the engine had run a total of about a minute, if it had been started at all. Real hot rods had grungy, rusty headers that showed their wear with pride. Trouble is, the wear wasn’t just cosmetic. As headers are used, the continuous process of hot-cold-hot-cold cycling wears away the metal. At first the result is discoloration, but before long a trip to the speed shop for a new set of headers is required. Notice we said it used to be that way.
Modern technology has done wonders for the automobile, from carbon-fiber body parts all the way down to the computer-designed camshaft in the lowest-buck, beater street machine. The high-tech development that has solved the problem of burned-out headers is the metallic-ceramic coatings that have come from the aircraft world, including those available from Jet-Hot. This coating not only keeps headers looking new for years, but also protects them from thermal fatigue (which is what causes holes in the header tubes) and can sometimes lower both engine water and underhood temperatures.
The coating process starts with Jet-Hot cleaning and blasting the headers to rid them of any contaminants, then spraying them with an aluminum base. On top of the aluminum base is a ceramic envelope, and the two are held together with a proprietary binder, or glue. The ceramic isn’t the conventional, brittle ceramic that usually comes to mind. It’s much tougher and won’t crack or flake off.
The main benefit of the coating from a performance standpoint is that the metallic-ceramic combination holds heat in the pipes, which in theory improves exhaust scavenging. Getting the gas out faster also means the cylinder heads run cooler, which lowers the operating temperature of the engine. Also, because the heat is better contained within the header tubes, less is radiated into the engine compartment, and underhood temperatures come down. Lower underhood and engine water temps mean the intake charge becomes more dense, which makes power. Another benefit is that since the pipes don’t radiate as much exhaust heat, they cool more quickly, a plus when you’re trying to change spark plugs on a hot motor.
For many people, however, the selling point for these coatings is their appearance. The shiny silver coloring stays that way for a long time, unlike paint that burns off almost immediately, or chrome that turns several shades of blue just as fast. Not only does the coating not discolor, but it can also be hammered on and scratched without flaking off and without sacrificing any metal protection. The coating more or less “becomes one with the metal” and is electrochemically active, so that even if it is cut through to the base metal, as long as the cut is 1/16 inch wide or smaller, the metal is still protected.
The metallic-ceramic coating is also applied to the inside of the header tubes, which not only works to lessen thermal fatigue, but also may have some positive effects on exhaust flow. We haven’t had a chance to do a flow-bench test of a coated versus an uncoated header, but theoretically the coated pipe should flow better due to a smoother bore. Also, rust forms inside uncoated headers after usage, which restricts flow slightly. Since the coating is only a few mils thick, it doesn’t measurably decrease the tube’s diameter.
Jet-Hot works with several header manufacturers so that coated headers can be purchased directly from the manufacturer. But the company does most of its business with individual consumers, and the headers don’t need to be brand-new to be coated. Jet-Hot will coat a set of used headers for the same price, and they’ll even fix small pinholes or minor imperfections. This is especially advantageous when dealing with a custom set of headers, such as in racing or engine-swap applications. A lifetime rust-through guarantee is offered when new headers are coated, but that doesn’t apply to used parts. However, the company focuses on customer service, so there’s a money-back guarantee if you don’t like the coating once you get the headers back.
How long does the coating last? Well, nothing lasts forever, and the lifetime of any component depends on how hard it’s used. Headers on a race car in Southern California will obviously last longer than those on a daily driver in a nasty climate, such as in Chicago, for example, but Jet-Hot claims its coating will outlast anything else on the market. A safe estimate would be that the headers will last two to three times longer than if they were uncoated.
Jet-Hot has also made the procedure for sending the headers in to be coated as painless as possible. All sales and tech calls go through the company’s Pennsylvania offices, but there are facilities in Mississippi and Arizona that cut the turnaround time dramatically. Jet-Hot provides the Federal Express number to customers, and Fed Ex picks up the parts at your door and delivers them Second Day Air to the nearest Jet-Hot facility. Once coated, the parts are then Fed Ex’ed back to the customer at no extra charge. Normal turnaround time is 72 hours, but racers in a hurry can request a 48-hour turnaround for no extra charge. If you really can’t wait, they’ll get ’em back to you in 24 hours, but that costs more. The cost is the same for new or used headers: $220 for internal and external coatings. Opting for just the external coating only saves about $30, so it’s worth it to get the full treatment.
Jet-Hot isn’t the only company offering coatings for headers and automotive parts, but it is one of the biggest and strives for the utmost in customer service. So now there’s no excuse for having ugly, crusty headers on your hot rod.
