24-05-2022, 07:31 AM
(This post was last modified: 24-05-2022, 07:37 AM by Colin Morgan.)
You are right, I have forgotten about the heat lost in the exhaust. It seems a better estimate of where the energy from combustion goes would be, as you say, 1/3 mechanical work, 1/3 heat lost in the exhaust gases, and 1/3 removed by the cooling system.
I have measured the top temperature in the radiator in the past, and the temperature of the bottom hose was estimated - it was about as warm as bath water after a run. So the temperatures are about right? (Ambient temperature was about 15 degrees.) Therefore, taking the above calculation where 7.6KW is lost through the radiator, and the 1/3, 1/3, 1/3 split this would correspond to a useful work output of 7.6 KW which is 10.2 bhp - so the engine would need to be working harder to produce that heat load on the radiator and the flows given above - perhaps a speed of more like 40 mph?
I have measured the top temperature in the radiator in the past, and the temperature of the bottom hose was estimated - it was about as warm as bath water after a run. So the temperatures are about right? (Ambient temperature was about 15 degrees.) Therefore, taking the above calculation where 7.6KW is lost through the radiator, and the 1/3, 1/3, 1/3 split this would correspond to a useful work output of 7.6 KW which is 10.2 bhp - so the engine would need to be working harder to produce that heat load on the radiator and the flows given above - perhaps a speed of more like 40 mph?