How many RPM's?

[JohnsonM50]

I don't understand many things, but help me understand how cars like the 1970 buick gs 455 stage 1, with 455 cubic inches, and only like 375 horsepower (also only had a hydraulic cam) could pull that big heavy car down the quarter at 12.5 with a 3.42 rear and air conditioning? I always heard it was because it was such a torquey motor, but surely a solid lifter 454/450 ls6 chevelle, or even a 396/375 (both 454 and 396 with solid lifters) would smoke the buick, but they didn't seem to. In fact, it seemed to get the 454 and the 396 into the 12 range you needed 4:56 gears or so.

Any thoughts on why this was? The point is, if you do the math of h.p. X rpm = torque, it seems the ls6 would be much better at pulling weight down the 1320, but i don't think it was. I know, i know, set-up is everything, but it sure seems those buicks would require less set up and run faster, and i am not really a buick fan.

Curious, please school me up. Thanks ronny

From what Ive heard Buick performance engines developed alot of power from the low R ranges. If you think about it getting off the 'stand still' is where that time is saved.

[Ron Hill]

Gordy explained that 5250 is where RPM and torque cross, but he said he'd check for me (Because it is a computer formual), but he thought it was Maximum horsepower divided by maximum rpm divided by 5250...Then he said, I've been up since 6 A.M. I need to think about this...

So.....Paul Pfaff's Gordon Jennings Jr. will help us, but not today!

He did pick up Trafficades' J Hydro for his kid, Gordy III...

[fyremanbill]

Torque is a measure of twisting force. Imagine your torque wrench applying 100ft lbs to a large, stationary bolt. It's not moving, and doesn't create power...horse or otherwise, until it is applied constantly to a moving shaft. Think like the cranks on a bike.

Horsepower is a measure of work done in a given period of time. The same work can be done by applying a small amount of torque to a faster moving shaft, or a greater amount of torque to a slower moving shaft. Try it both ways and you can see for your self using the formula: torque x RPM, then divide by 5250. This coincidentally means that the torque value will also mathematically be the same as hp at 5250 RPM. Even if it's only 2 ft lbs.

This has nothing to do with the RPM at which a given engine will produce it's torque or hp peak. My diesel pickup will produce about 500ft lbs, but at under 2000 RPM. Some high speed racing engines will produce their peak torque near 10,000 RPM, but the same formula is used for both examples to calculate hp.

And yes Sam, there are some simplifications in the above to make it easier to understand.

[Mark75H]

It works for me

[194265]

Works for me too. Now to mess we you all a little bit, the constant is realy 5252, but then you all knew that, right .

[fyremanbill]

Works for me too. Now to mess we you all a little bit, the constant is realy 5252, but then you all knew that, right .

That's right...it's been forever since I've done any of the calcs manually.