If you’re a big time racer, you know how much punishment your pistons take. Diamond Pistons has introduced the first production piston with a combination of heat-resistant, friction reducing coatings. This coating has particular benefits for engines with power-adders.

Official Press Release

DOUBLE-DIAMOND COATINGS: FIRST PRODUCTION COMPETITION PISTONS COMBINING HEAT-RESISTING WITH FRICTION-REDUCING COATINGS

Clinton Township, MI: Diamond Pistons has introduced an ambitious new formula—a notable step forward in piston performance—the Diamond double-coat.

By combining hard-coat anodizing with a moly-skirt coating, Diamond’s double-coat pistons will benefit all engines but is particularly useful in power-adder applications.

The anodizing process provides a thermal barrier and increases both corrosion-resistance and wear-resistance. It also deters piston rings from micro welding themselves to the ring grooves and it creates an excellent adhesion surface. The baked-on molybdenum dry-film lubricant skirt coating provides an anti-friction anti-scuffing surface; hence this new combination resists high cylinder temperatures and pressures and frees-up a little more power.

To compensate for the additional build-up from the anodizing process, extra machining clearances are required, about .002-inch on the piston diameter and also on the width and depth of the ring grooves. Then the pistons are submerged in a detergent-acid bath, followed by two rinses before the anodizing process and three rinses after.

In the coating room, five light coats of the moly dry-film lubricant are applied to the pistons, which are then baked in an oven for an hour.

Diamond, who has been developing and testing their double-coat procedures for over two years, conducts all their coating processes in-house. The turn-around time for the Diamond double-coat process is about two days and the cost is $50 per piston. Single coatings, either anodizing or moly-skirt, are still available.