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PopinJohn 10-21-2009 17:10:47 207.119.235.26 250386 Report to Moderator	Hi Guido, I agree, 5252.1 is the constant used in the formula. The formula you present is correct. But, a constant has to be rooted in math. 5252.1 is equal to 33,000 ft/lbs. divided by 6.2832. [6.2832 is (pi 3.1416) multiplied by 2]. That's why I was pointing out that "because of the formula, 5252.1 RPM is the point where a torque curve and and horsepower curve always cross on a engine spec sheet". As an example, HOT ROD magazine publishes dyno result charts with both the HP curve and the Torque curve. These are high output racing engines with the capability to turn on up to 6000 RPM or more. The curves always show HP and Torque to be equal at 5252 RPM. Try it this way: Find Torque = 39Hp x constant 5252 divided by 5252 RPM. The constant and the RPM cancel each other therefore Torque = 39, same as the horsepower. [Reply]   [Send Email]
GUIDO 10-22-2009 13:06:33 71.168.249.124 250438 Report to Moderator	Hello PopinJohn, You have applied the formula correctly. As you calculated if the RPMs'S are the same as the constant, HP. AND TQ will be the same. You also have to remember that a 4 cycle engine USUALLY has the torque and HP peaking at different RPM'S. After they peak, the output goes down. You got it! ..........Guido.   [Reply]   [Send Email]