Druid,
Try Googling "propcalc" - it will give you a different set of programs
and some of these, including the freeware excel program named
*PropCalc*, will require input of engine horsepower. In fact, PropClac
requires it in the first entry.
The following is a copy of the first calc page. Some of the entries are
user inputs, some are the calculations. For ex. you put in engine
horsepower and max rpm, and out comes torque, etc.

45 Engine Horsepower
2000 Engine R.P.M. (max)
118 Engine Torque ft/lb

44 SHP - Shaft Horsepower at gearbox output.
3 Enter number of bearings between gearbox output and propeller.
1.50 Enter Gearbox reduction ratio. Eg. 1.5

4.50% Percentage power loss due to shaft bearings.

44 Shaft Horsepower at propeller.
1333 Propeller RPM
172 Propeller Torque ft/lb


Red

On Fri, 19 Oct 2007 11:01:33 -0400, Red wrote:

....
118 Engine Torque ft/lb
....
172 Propeller Torque ft/lb


Red


This is a nit-pick, but everyone has his hobby-horse.

A measure of work is raising some weight through a particular height.
If you time how long this takes, you have an early way of specifying
power - James Watts's way, in fact.
That's feet times pounds all divided by time .
For example ft.lbs /min

A measure of torque is how much force a crank can apply at a given
distance from the shaft's axis of rotation.
This does not signify power, or work but it's sometimes good to
know.
The units for torque can be force in pounds TIMES distance from the
center in feet. This time, the force is at right angles to the
distance from the rotation axis. So it can be given as ft.lbs
also, but this makes it look like work, just one step away from power.
But it isn't.

So some people who like to keep the difference between work
and torque in mind, call the one unit ft.lbs
and the other unit lb. ft.

To summarize: there is no such unit as ft/lbs.
/ means divide by....
There, I said it! :-)

Brian W