Racing Engine Protection - Parts Coatings

Engine coatings protect metal in much the same way a coat protects you. Your coat might protect you against cold or heat, or even against friction. Metal coatings do the same things. Some coatings are specifically for friction reduction, while others form thermal barriers.

Tech Line Coatings produces these products, and many of the coatings are available in small sizes for the racer wanting to treat his own parts. And while they aren't as easy to slip into as your favorite old jacket, applying parts coatings isn't a high-tech endeavor. If you can assemble an engine for your race car, you will be able to perform the metal coatings we describe here.

Almost every part in an engine can benefit from some type of coating. Blocks are coated internally to increase oil drain-back. Cylinder walls and lifter bores are coated to reduce friction. Lifters are treated on their face to reduce cam wear. Cylinder head ports are treated to increase flow for a given size. Combustion chambers are coated to keep the heat in the chamber where it is put to work. Piston skirts are given a friction-reducing coating, while piston tops are treated with the same thermal barrier shield as the combustion chambers.

We've not named all the parts in an engine, but you get the idea. For about 100 bucks or so, you can coat almost everything under the hood.

Parts coatings aren't new. I first used some of them a number of years ago. What I haven't seen, or at least no one admits to, are some creative uses for coatings. If you have ever burned a pinkie or two on a hot rearend, you might think about reducing its friction. Treating the ring-and-pinion with Tech Line's DFL-1 friction-reducing coating can make a difference. Even the bearings in the rearend can be coated. Coat the inner and outer races.

If you run a class requiring four-wheel brakes but would like to run the equivalent of three-wheel brakes, DFL-1 antifriction coating applied to the right front brake rotor would give some braking bias toward left turns. While you have the front end apart it wouldn't hurt to coat the front wheel bearing races.

On IMCA cars, which use coilover eliminators, the suspension could be freed up a bit with a friction-reducing coating on the sliding parts. Along this line, think about the driveshaft. If your car has much sliding movement in the spline area, this can be a source of friction causing suspension bind. If yours is a leaf-spring car, coat the leaves to reduce the sliding friction between them.

In short, these coatings will help reduce friction or contain heat anywhere you put them.

Ken Mullinex, a technical assistant at Tech Line, offers some advice on choosing and applying coatings. He says to begin by selecting which part you want to coat and for what reason. For instance, let's examine a piston. We would want the piston to slide easier in the cylinder bore. This reduction of friction produces less heat. By sliding more freely, less power is lost to friction. Mullinex suggests DFL-1, a dry film lubricant.

Mullinex says this is only half the picture when looking at a piston. Using CBC2 coating on the top of the piston forms a thermal barrier. This means the heat generated in the combustion chamber doesn't leak out through the pistons. The more heat retained in the combustion chamber, the more push there is on the piston.

Less friction in the engine and keeping heat in the right places will result in more power. Then, jetting and other tweaks can be adjusted for even more power.

Coating the piston top to reflect heat is only a partial job. The combustion chamber in the head absorbs a lot of heat, which is transported to the radiator where we use more power to dissipate it.

The same CBC2 used on the piston top can be used to coat the combustion chamber surface and the face of the valves. At this point everything in the combustion chamber except the cylinder walls will have a thermal barrier coating.