Correct. Torque always peaks below HP since torque is the only thing
that matters. HP is just Torque x rpm x (constant). Torque goes up to
it's peak, starts dropping off. RPM keeps rising past the torque peak so
HP rises at a slower rate then drops off.

Google on "torque curve" lots of nice articles
http://www.dur.ac.uk/r.g.bower/PoM/pom/node11.html
http://www.auto-ware.com/combust_bytes/p_goal.htm

SteveF wrote:

"wwsjr" wrote in message
m...

Leo Lichtman wrote:

Besides that, the HP "rating" of an automotive engine is developed at a
certain RPM at full throttle. Unless the car is on a dynamometer, it
would be almost impossible to operate it for any time at that point.

Aircraft engines are operated at near peak torque for long times.
Experimenters are having good luck with Subaru engines, my favorite (the
Pietenpol), used an inline 4 cyl. Ford.
Key items are cooling and lubrication, one needs to start with a good
design, as most modifications are patches at best.

wws


It's been a while so someone correct me if I'm wrong but IIRC peak torque
occurs at a much lower RPM than peak HP.
For a good size Ford V8 it was something like 3000-4000 RPM for peak torque
and 5000-6500 for peak HP.

Steve.