Cubic Inches...
5252 is the constant that connects the definition of 1 horsepower (550 lb/sec) to rotational speed in RPM. 360 degrees = 2 * Pi radians = 6.2831853. 1 RPM = 60 RPS, so 60*550 = 33,000 lb/min/rev. Divide that by 2Pi and you get 33000/6.28 = 5252. This constant "connects" HP and TQ at any rpm.
sorry just got back to the office... If takes a sharper mind than mine to explain it, I was never good at math and hate formulas...LOL
trigonometry isnt it?
But I have had a conversation or two with Erik about various things
trigonometry isnt it?
But I have had a conversation or two with Erik about various things
Last edited by 99blancoSS; Dec 9, 2008 at 01:00 PM.
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5252 is the constant that connects the definition of 1 horsepower (550 lb/sec) to rotational speed in RPM. 360 degrees = 2 * Pi radians = 6.2831853. 1 RPM = 60 RPS, so 60*550 = 33,000 lb/min/rev. Divide that by 2Pi and you get 33000/6.28 = 5252. This constant "connects" HP and TQ at any rpm.
Usually the stumbling block for many is 1 rev = 2(Pi) radians. A radian is defined here (from Wikipedia):
"The radian is a unit of plane angle, equal to 180/(Pi) degrees, or about 57.2958 degrees. It is the standard unit of angular measurement in all areas of mathematics beyond the elementary level.
It follows that the magnitude in radians of one complete revolution (360 degrees) is the length of the entire circumference divided by the radius, or 2(Pi)r /r, or 2(Pi). Thus 2(Pi) radians is equal to 360 degrees, meaning that one radian is equal to 180/(Pi) degrees.
However, the radian is mathematically considered a "pure number" that needs no unit symbol."
^^^That helps make the units work out for the math majors.
Is everyone clear on that now?
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Bore times bore times stroke times .7854 times 8 or:
4.005 x 4.005 x 3.622 x .7854 x 8 = 365.035 or 365 cubes.
26 keystrokes on the old calculator.
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I did already, just after post 4 was posted to be exact. You guys are just confusing the hell out of me with all these decimals. 
Thanks again for the info. 
