Not really.

Torque is an instantaneous measure of force at a given moment.

Horsepower is the measure of work being done over a period of time.

Once those concepts are understood, then it's easy to sort through what is fact and what is BS in this thread.

 

Torque= size of fist.

HP= how fast fist moves.

 

Groundhog Day
Groundhog Day
Groundhog Day
Groundhog Day
Groundhog Day
Groundhog Day

 

No this post is good, I had another thread going and Pocket says HP is HP then people would post and say no it isn't my Diesel pulled way better than my gas engines and he would battle back and say yes it is.


What you say is what I have been told and you can only gear around lack of torque to do a job to a degree.


The V 10 is a great engine but does not have the torque of a good diesel, you could not give one of the new diesels however, to complex and expensive.


Even engine builders some of them do not understand what torque HP #'s mean in the real world, It is my belief a 500 HP Semi engine is way way way more powerful than a 500 HP engine that spins at 7 or 8 thousand RPM and has way more ability to build and maintain HP ( MPH ) under a big load.


If I am wrong I am wrong however. By the way I read somewhere Pocket got a new truck hopefully it has the torque to do the jobs he asks of it.

 

Can a bunch of fly weight punches do the job of a big fist that punches less ?

 

I did not realize you were back, please explain this if you would not mind.


This is kinda what got me thinking about this a long time ago. I have 2 motorcycles, each one makes 55 RWHP on a dyno at the rear wheel. One makes the 55 at 5500 RPM and the other 55 RWHP at 8500.


Both machines geared correctly will go max 100 MPH exactly the same speed within a MPH all things being equal but if you have both machines geared to go exactly 50 MPH redlined in 3rd and you pull the clutch in going like 3 MPH and rev both bikes to the moon and drop the clutch why will the one motorcycle with a 300 pound rider aboard that makes peak power at 5500 RPM throw you off in less than a second and the one that does it at 8500 RPM stall with all gearing being the same ?


Is that not what torque does ? more pulling power under a given load, so the lower RPM motor is more powerful at moving a heavier load all things being equal ?

 

It's real simple.

STOP INTERCHANGING TORQUE AND HORSEPOWER. THEY ARE NOT SIMILAR UNITS OF MEASURE.

 

Keep it civil, please.

 

Like I stated I pretty well understand it now , you break it down to a degree so thanks.

 

That would depend on how the force is delivered, for instance, Bruce Lee was small in stature, but could deliver a mighty blow.

 

The semi I used to drive was rated for 550 hp but it put down around 2000 ft/lb or so it was rated for. However I think there are so many factors involved in figuring out that its easier just to find what works best for you than to try and compare a small pickup to a truck like that. Then you have to factor in the 3 drive axles and how it is split between them. The gearing in my opinion is the most important factor than any of the hp or torque numbers these manufacturers throw out there. I've seen a few automatic semi's with 100+ hp more along with the same torque rating than me but a higher gearing that couldn't pull an identical load up the same hill as me. They would start climbing and get to a point and the wheels would just stop turning. I'm also talking about 14% grade hills or bigger so you really get a good measure of what you can pull when you try to get 55,000lbs+ loads up there .

 

If you go to www.dictionary.com you can look up the definitions for horsepower and torque.

 

You can't keep changing both variables when making a comparison..

one or the other is constant.. either torque, (size of fist), or HP (speed) is constant.

will a small fist do as much work as a big fist at the same speed? No..

I know what your argument is. A gasser can use RPM to it's advantage.. Well, kinda yes, and kinda no..

Gas engine's torque reading and HP reading cross on a dyno chart MUCH higher in the RPM band than diesel. At high RPMs, TQ drops off (sometimes drastically) and the gap between torque and HP gets bigger the more RPMS you turn.

So, can more RPMs help a gasser?

Yes, if you run it at the RPMs where TQ and HP cross.. Think of punching fast with a normal fist. (i.e towing somewhere around 55 in 1:1 trans ratio. (for me, thats 3rd gear))

No, if your running way up in the range near the red line. think of punching faster with a smaller fist... (i.e drag racing in an empty truck)

Running at the rpms that constitute peak torque, Think of punching slower with a bigger fist.. (i.e. pulling power, getting a load to move)

Your comment seems to kinda humanize TQ and HP, and it can't be compared that way. Humans are irrational and emotional. TQ is rational, and scientific. It does not care about momentum, (big guy, small guy theory) or how it is used. Momentum only prolongs the TQ event. (e.g hitting a wall with your fist, (short duration TQ event, or driving your fist through it, (long TQ event)), does not add torque, only prolongs how long you can maintain TQ. Momentum in an engine varies with RPM, but the difference of a few thousand RPMS while under a load is very minimal. Generally, it is pretty constant in an engine.

 

Different engines turn at different ideal speeds by design.
Your diesel maybe pulls good at 2000 rpm....but it cannot spin at 5000 rpm.
Your gas maybe pulls best at 4000 rpm because that is its design.
A rotary engine may work best at 7000 rpm because that is its design.
A motorcycle may work best at 14000 rpm....again by design.
A jet engine may work best at 36000 rpm....yup you guessed it. By design.
If your working any engine hard and need it to produce full power just run it at the appropriate rpm for its intended design.
Comparing it otherwise is pointless.
The turbines in my helicopter make way more power than your ford diesel. But at a different rpm.
A huge engine to run a generator station that powers say a small village will make a lot more than my helicopter can.
Just run what you have at the right rpm for it and stop worrying about if it turns more rpm.
Pulling your trailer up a hill just do it where your particular engine design works best.
If diesels are so much better at making power why do the dragsters in NHRA not run them?
Its silly to argue apples to fish boats.
If you want more power buy a huge engine like used in a generating station.....nope not practical. .....but damn they make massive amounts of power.