Yuu -

Your point is well taken. The COX design differs from almost all other IC engines in that the rod/piston joint is located at one of the hottest points in the engine. Heat must conduct to the edge of the piston and down the skirt to be drawn off into the cylinder walls and dissapated into the fins. For the typical rod/wrist pin setup, heat comes from the cooler skirt wall and migrates along the wrist pin. A lower heat source coupled with being bathed in a cooler fuel/air mix allows the rod bearing to run much cooler. Add the fact Andy made about more area being exposed to lubricant vs the shrouded ball joint in COX engines and you have a recipe for early failure without good lube.

One thing I believe gets overlooked regularly, except by us old f**ts who flew the iron/steel setups of past years, is that castor carries a lot of heat out the exhaust. The synthetics, with a lower flash point, burn adding heat to combustion. Thinner synthetics likely don't help cool the ball joint. Castor can be really efficient in cooling the joint and maintaining good film strength.

I'm inclined to believe that film strength and a high flash point are the two properties that give castor the advantage with COX engines.

That's ma' story and Ah'm stickin' to it.

andrew