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Comments by: Tom Ballou@Sherwin@RawMatDiv
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Wrong Dan, more HP does equal more heat. Heat is what does the work in your
engine. Typical internal combustion engines are only about 25% thermal
efficient, meaning 75% of the input energy is wasted and must go somewhere.
Some is consumed in pumping losses. A fair amount goes out the tailpipe
(feel the exhaust sometime - or turn out all the lights in the garage some
night and rev up your engine - watch the headers glow), some is radiated
directly from the engine (that's how air cooled engines get rid of their's)
and the rest must be extracted by using some type of exchange medium - water
or oil - and dumped into the air through some type of heat exchanger (a
radiator or oil cooler - oil pan). At 25% efficiency, in order to get 1 hp
at the rear wheels, you have to put 4 hp worth of energy into the engine;
most of the extra three leaves either as pollutants (unburned hydro carbons,
CO) or as sensible heat. The bigger valves increase the volumetric efficiency
of the engine by allowing a freer flow of intake gases and a freer flow of
exhaust gases. More gas (here we mean air/fuel mixture) in, more heat
generated, higher cylinder pressures, more force on the pistons, more torque
on the crankshaft, more work performed at the rear wheels. Hp is a time
study of the work performed. Still, increasing the volumetric efficiency
doesn't change the thernmal efficiency, so you still have the 75% loss
problem resulting in more waste heat. If you don't upgrade the heat
management system somehow when you increase the hp output, you will have
trouble.
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