HP vs Torque vs RPM

[RSmith]

Hi Guys,

Please tell me if I'm right or wrong. This is how I understand it.

HP x 33,000 / C / (RPM/2) = T

HP = Horsepower
C = Number of Cylinders
T = Torque in lb/ft

Is this correct???

 

[HDi fun]

They're only numbers and units of measure. No of cylinders is of no consequence.

 

[RSmith]

They're only numbers and units of measure. No of cylinders is of no consequence.

Right... but horsepower is torque per minute. So, surely an engine with more cylinders will have more power strokes per revolution and therefore per minute. That means more horsepower can be given from a lower RPM.

 

[HDi fun]

Right... but horsepower is torque per minute. So, surely an engine with more cylinders will have more power strokes per revolution and therefore per minute. That means more horsepower can be given from a lower RPM.

Nope - number of cylinder is not relevant.

Torque is a measure of force only. It's only angular force. Number of cylinders, although this will influence the way torque is delivered, has no bearing at all upon the measured figures.

 

[obi_waynne]

RPM is the constant here, a 6 cylinder and 3 cylinder engine will still have the same RPM despite the fact that they use a different number of strokes to achieve this, so you don't have to factor cylinders in to the equation.

 

[davevm]

check this page
http://craig.backfire.ca/pages/autos/horsepower