Bill, i knew that[tongue in cheek], you left out the coeffient of friction Mu=F over R. When you think about it engines are only 20% efficient, 35% heat loss into engine components and cooling system, 35% heat loss into exhaust, 5% airflow loss, 5% friction losses. That leaves 20% of the fuel burn to act as torque on the crank. If we could harness those losses we would not need dynos the bum meter and fear would tell you when to change. Turbos are a good start, the ultimate reciprocating poppet valve engine would be full polished ceramic, tight tolerances[same expansion rate] no oil no cooling no rings or brgs very little friction small heat loss and last forever. Trivia from my Tech days, definition of friction, the interlocking of the minute hills and hollows of two opposing surfaces. Its 5am in Oz cant sleep hence the rave. Regards Jack McIntyre.