[DML] Re: Questions on Houstons engine

["content22207" <brobertson@xxxxxxxxxxxx>]

You've already answered your own question: "it does this at a higher
RPM". HP is calculated: Torque x RPM / 5252. In an engine so capable,
increasing RPM will increase HP -- it's a mathematical certainty. Note
however that every engine has a point of maximum power output, after
which increasing RPM only produces more noise (HP and torque will
actually go down, sometimes precipitously). This is the engine's power
curve.

People get all strung out over HP, yet a HP number by itself (without
the RPM's at which it was calculated) tells you very little. A high
torque engine operating in a fairly narrow power band may post low HP
numbers, but is actually more powerful than a low torque, high rev'ing
engine with higher HP numbers. That's one reason you never see a
sports car towing a boat trailer. Note also that such an engine is
useless until it rev's up to its power band -- if you can't get there,
you have nothing. Standing still, that 300 HP sports car hooked to a
boat trailer would either stall, or burn up its clutch/clutch discs,
trying to move.

Back to your original question: Houston has obviously raised both
torque and the PRV power curve. I suspect the former is achieved with
increased compression (doesn't displacement remain 2.8L?). The latter
is probably a result of higher/shorter duration cams, perhaps bigger
valves, and ignition timing. Houston's engine is still normally
aspirated -- freer flowing intake/exhaust will help, but not 60 HP
worth. Nor will lower friction components alone.

Bill Robertson
#5939



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