Tim,
Sorry, but I have to disagree with this whole "reciprocating mass
acceleration/deceleration" loses horsepower argument. One might think this
it true if you focus, for example, on the motion of a single piston, but for
every part of the engine that's accelerating, another equal mass is
decelerating. That's an inherent property of a "balanced" engine, or even an
unbalanced one if you let it rotate about its center of mass like a washing
machine, so the rotational energy of the engine stays very constant
throughout the cycle; that is, up to the point where it breaks, which
happens sooner with heavier pistons, etc. So, other than some increase in
friction because of increased areas and loading, there is no more energy
lost due to "reciprocating mass acceleration/deceleration" in a big engine
than in a small one since they are both zero. Engines are dyno'd at
essentially constant rpm, so the effects of accelerating/decelerating are
not a factor, just the steady-state HP output. The rotating kinetic energy
put into the engine during acceleration is recovered during deceleration;
for example, popping the clutch on a big block versus on a small block
engine.
Bob Palmer
rpalmer@ucsd.edu
rpalmerbob@adelphia.net
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