[Marv D]

That's a two edged sword. HP is just torque / 5250, times rpm. Torque is all a dyno can measure. HP is just a function of that torque and the rpm.

So.... a motor that makes 600 ft pounds of torque at 4000rpm is making a whopping 371 HP (not impressive is it)


Same 600 ft pounds at 5250 is 600HP (at 5250 HP and torque obviously are exactly the same) at 7000rpm 600 ft pounds is 800HP. See what I'm getting at. Just because a hydraulic roller motor is all done early in the rpm game,, it is STILL making buttloads of power.

A high reving small block making 420HP at 6500rpm is only making 340 ft pounds of torque.

Think of it this way. TORQUE accelerates the car. HP will make MPH in a heavy car.

As an example I rode in a buddys Powerstroke, chipped POS with propane injection, 1ton dually 4wd crew cab,, this animal had to weigh 7500 pounds and we had 4 guys in the truck. When he stabbed the throttle I about crapped my pants. He would DEFINATELY outrun my 3600 pound 12 second pickup until he ran out of gear / motor. Torque is KING on the street. Torque is the twisting effect on the drive shaft,, more of it AT ANY RPM is going to accelerate harder than slowly building RPM to get the same job done.

The 383 making more torque below 5250rpm is a more powerful motor. BUT because the 355 is making similar torque in a higher rpm range, the two could EASILY have the same PEAK HP. Even if the 383 had a buttloads more torque in a lower rpm range. Stroke will do that for you. More stroke = more torque. More stroke also means more piston speed, more friction loss,,,, more reasons to keep the RPM's down and accelerate away from the high winding little 355 that has to gain more rpm to make the same 'power'.

So Scott saying there was no PEAK HP improvement was VERY believable. But if the dyno were a race car,, the motor that had more torque (in a usable rpm range) would be at the finish line first.

Is that about clear as mud. I don't 'splain' things too well sometimes.