Horsepower ratings

[treerodent]

Does anyone know how they rate horsepower on tractors these days? I got an old tractor that pulls a plow, disc, 8ft grader blade, etc and it is rated at 24horse (I think its 24 horse or somewhere close to that). I see lawn mowers with higher horsepower than mine and I know they don't have the pulling power that mine does.....any ideas on this? It has always seemed peculiar to me.

[timwilcox]

The way they rate HP is put a Dyno on the PTO. It puts a load on the engine which rates the engines horsepower.

[bigpat]

Strange isn't it? Do you think your tractor can pull near what 24 horses can?

[Admin]

I've always wondered about this too. I know for certain that 10 horses could out pull any 10 horse motor on the planet. Just never understood the horsepower thing.

[bigpat]

I know this doesn't actually clear anything up, but a horsepower is the amount of energy required to move 33,000 pounds one foot in one minute. Like TW said a Dynamometer measures this. What an engine is capable of producing and how much is actually converted to the PTO or axles can be very different. Obviuosly a horse can't move 33,000 pounds a foot in a minute, but he can move 330 pounds 100 feet in a minute. It all adds up the same. One horsepower is equal to 746 watts, 2,545 BTUs, and 641 calories.

[treerodent]

Thanks for clearing that up Tim.

[Admin]

Now that we have the horsepower figured out, what else can we talk about?