Horsepower is horsepower?

wilber1 wrote:

RCMAN46 wrote:

BenK wrote:
Another try in explaining how torque is the basis for HP...



Then allow that drive shaft to move 1 degree in rotation from that
100 lb weight hung at exactly 12 inches from the drive shaft center
line

Wrong what if it took two years for the drive shaft to move that 1 degree would that still be 1 horsepower?

The main problem with these discussions most have no idea what the definition of a horsepower is.

He is right, there would be horsepower generated. I don't see where he said it would be 1 horsepower. It might only be .0001 horsepower but it would still be horsepower.

Maybe whole HP's might help....

Take that drive shaft and a 100 lb hung 90 degrees or horizontal
exactly 12 inches from the center line of the drive shaft

Do NOT allow the drive shaft to rotate

You now have 100 ft/lbs of torque and no HP. As HP needs both torque
and RPM (time based unit)



Now allow that 100 ft/lbs of force to be mounted on a wheel 12 inches
in dia, mounted on the drive shaft and now allow that wheel to turn 100 RPM

No torque until the drive shaft moves...and the formula

HP = torque x RPM / 5252

looks like this:

100 x 100 /5252 = 1.9 HP



Since ICE's spin in thousand of revs, use 3,000 RPM in the above
forumula so it looks like this: 100 x 3,000 / 5252 = 57.12 HP


So to get more HP, either increase the torque, or RPM...or both



Then we will get into the laws of physics of BTU per unit of fuel,
the crank throw (that lever arm of 12 inches above), the numbers of
cylinders (number of throws), and a host of ETC's. Some particular
to one vs the other that messes up so many folks so that they get
confused between ICE's

Must comment on CR...they should stick to toasters where their PhD's
are competent...I do not listen to anything they say bigger than a
toaster oven or washer. Ditto references to their expertise...a personal
thing