Coated Bearings

The purpose in coating bearings, as well as other engine parts, is not only to reduce friction but to provide a more durable surface. Developed in 1995, our exclusive HM-30 coating is made up of many different types of dry film lubricants which, when combined, have a wider range of temperatures than oil or other lubricants alone.

After using coated bearings, Elliott found he could go tighter on clearances without getting into scuffing problems. After tightening the rod and main clearances, he found that there was more oil pressure. By backing down the pressure to where the engine would normally run he experienced a drop in oil temperature. It would seem that going tighter with bearing clearances would increase oil temperature, but smaller clearances mean not as much oil is escaping by the shaft and bearings, and being whipped around the crankshaft, counterweights and other moving parts, which is generally the cause of higher oil temperatures.

Coated bearings will prevent cold start up wiping.

Cold start up can do as much damage to bearings as anything else because the cold oil is thick and will not flow well until it heats up and thins down. Race engines generally get rebuilt after every race, but if you are late-model you may not rebuild the engine but once a year.

Even though you don't generate as many horsepower, or turn as many RPMs, the bearings still get beat up due to cold start up. In most cases the engine gets shut down on Saturday night and all of the oil runs off the bearings and crankshaft. The engine may not get started up again until the next Saturday afternoon. It takes a little time to pump some oil to the bearings, so they run dry for a short amount of time but just long enough to do some damage. This is where coated bearings would make a difference!