Charles Vincent wrote:
RST Engineering wrote:
I could be very, very wrong, but my understanding of efficiency is
that 25% efficiency means that a quarter of the energy goes to torque
and 3/4 to heat. That would mean you throw away THREE
horsepower's-worth instead of four, no?

Jim



since such engines are no more than 25% efficient when it comes to
converting the heat of combustion into torque at the crankshaft. That
means that for every horsepower measured at the crank you must
generate at least four horsepower's-worth of heat in combustion.


You are correct, but that is also exactly what he said ---. i.e.
generate four hp in heat, only one available at the shaft.

Charles


Well that's better than a 100 watt electric light bulb, which is a 90
watt heater and 10 watt light source...

John