There are numerous forces that work against your car's performance and your enjoyment of it, but one of the most prevalent is heat. From lowering horsepower, to breaking down fluids, to disrupting ignition, increasing wear, and just making you a sweaty mess, it's pretty fair to say that heat is your car's worst enemy.
From the factory most vintage cars have a small amount of heat management, such as the hood, firewall, and floor insulation, and maybe even a modest amount of exhaust heat reflection, but that's about where it ends. The materials and application may have been acceptable for low-powered stock cars 40-plus years ago, but things degrade over time. Plus, extra horsepower intensifies the heat production, so the limit of the stock stuff is quickly exceeded.
The best internal combustion engines are only around 15 percent efficient at turning fuel into power. The rest of it is lost as heat. The more you start asking of an engine, the more heat it generates, and the more it spreads through the vehicle systems and cabin. Basically our beloved pursuit of horsepower serves only to exacerbate the heat problem.
How so? Well, unless you have an air induction system that draws from outside the engine bay, such as a ram or cowl system, the air your engine ingests will be at the ambient temperature under the hood. How hot does your engine run? How hot are your manifolds or headers? It's not uncommon at all for underhood temps to hover way above ambient even when the car is in motion. Remember, most air entering the engine bay passes through the radiator. In traffic, things get even worse. Underhood temps can rise well into the triple digits. That same radiated heat creeps its way into the vehicle cabin and serves to raise the temperature and make your drive a sweat-filled experience. What's a hot rodder to do?
To help you concoct your plan to beat the heat and make your ride more powerful and more pleasant, we've pulled together our top 9 recommendations to contain, reflect, or absorb the infuriating heat. All of the companies we featured have far more solutions than we have space to cover here, so we picked out a handful of our favorites. Be sure to visit their websites for the full product rundown, and watch for installs in future issues of PHR.
You can’t beat the heat until you know where it’s coming from! Harbor Freight sells these Cen-Tech laser-targeted infrared sensing thermometers for under $40 and we use ours all the time. This is also particularly useful for testing the effectiveness of your product application and finding places you may have missed. As a bonus, it can be used for trouble-shooting, such as finding misfiring cylinders or reading cylinder-to-cylinder fuel distribution.
1. Exhaust Wraps
The engine block gets hot, but by far the biggest source of radiant heat under the hood of any car is the exhaust. With exhaust gas temps in the multiple hundred-degree range under throttle (the hot side of a turbo housing can approach 1,500 degrees), it's not hard to see why. There's nothing we can do to stop the heat here, but we can work to retain it in the pipes and channel it out to keep it from affecting other systems. One effective way is to wrap the hottest areas (the headers or exhaust manifolds) with insulation.
Thermo-Tec Generation II Copper
Thermo-Tec's Generation II Copper Header Wrap improves heat resistance up to 30 percent more than current technology, by using a new proprietary coating called Thermal-Conduction-Technology (T-C-T), which contains no asbestos. Continuous heat up to 2,000 degrees F is no problem, so it works well for turbo systems. In testing, Generation II Copper has also been shown to increase exhaust scavenging, bumping up power output.
DEI Titanium Exhaust Wrap
DEI's Titanium exhaust wrap is actually made from pulverized lava rock (LR technology), which is stranded into a proprietary weave that was engineered to be stronger than most wraps for extreme durability, yet it remains pliable enough for a tight and secure wrap. It has a very high resistance to abrasions, oil spills, temperatures and vibration breakdown, plus a cool carbon-fiber–like look. Good for 1,800 degrees F direct and 2,500 degrees F intermittent heat, Titanium wrap can be used on the hottest pipes and serves to increase flow for improved performance.
Coating the headers or manifolds is another method that works to trap the heat inside the pipe rather than radiating it outward. The coatings essentially work to make the steel itself less of a conductor of heat. They also have the added benefit of providing a tough barrier against corrosion.
Jet-Hot is the granddaddy of the coated header industry and everyone from hot rodders, racers, NASA, the U.S. Armed Forces, diesel engine manufacturers, and even the firearms industry uses their coatings to create heat barriers. They are continually improving their technology and options, like new custom print designs and colors in the coatings like this skull, or even color fades like the trick headers on the cover.
Either way, it still carries Jet-Hot's famous lifetime warranty.
If you already have a set of coated headers, that doesn't mean they can't be better. Most headers are not internally coated, unless special ordered that way. Internal coating works similar to the external coating by working to trap the heat inside the tubing. A header coated inside and out is very efficient at channeling heat out rather than radiating it. Eastwood's thermal coating withstands up to 1,800 degrees F and is easily applied at home on new or used exhausts with a 360-degree aerosol extension nozzle on a flexible 2-foot-long hose.
QFT Black Diamond Coating
Heat coatings aren't just for exhaust any longer. Quick Fuel Technology's (QFT) new Black Diamond coating is a heat rejecting outer coating available on all their carburetors. Carbs can see temperatures as much as 200 degrees underhood, and the chemicals in the fuel, oil, and coolant can literally bake onto a standard carb. Black Diamond is an impact- and scratch-resistant PTFE coating that not only prevents that, but lowers fuel temperature by about 6 percent to ensure maximum power and response.