Here is how I look at it...
If I was say comparing a high rpm engine that develops max. horsepower at
high rpm with maybe a diesel that develops torque at low rpm, I would
consider what gearing it would take to equalize the rpm's.
I'll pull some numbers out of thin air- a dohc gas engine that develops
maximum horsepower at 6000 rpm vs. a diesel that develops max. horsepower at
1500 rpm. Now let's put a 4:1 gearbox on the end of the gas engine so its
output shaft speed matches the crank speed of the diesel, and coincidentally
multiplies the torque by a factor of 4. The gas engine can thus br more
easily compared with the diesel.
> >I just ran across this little dissertation on the relationship between
>> and horsepower again. I haven't read it in several years and had to
>> re-educate myself.