kubota vs. kioti

[arlen4720]

Yes the tundra engine would pull the weight up the hill, and be able to maintain a faster speed doing so, If (and this if seems to be the part you keep missing)....

If it is geared to produce the same final drive torque.

Again, you can get whatever torque you want with gearing. But HP don't change.

Why aren't electric motors sold by torque?

Because you can use pullies, sprockets, and gearboxes to get whatever torque

When comparing to a flat torque curve engine, you may find that you don't have enough gear choices to make it work in a practical fashion.
I think everyone knows that gearboxes swap speed for torque. I thought the discussion was about the benefits of torque in a practical sense, not a theoretical sense. The relationship between speed, torque, and horsepower is too elementary to even debate.

 

[paulfun9]

Yes the tundra engine would pull the weight up the hill, and be able to maintain a faster speed doing so, If (and this if seems to be the part you keep missing)....

If it is geared to produce the same final drive torque.

Again, you can get whatever torque you want with gearing. But HP don't change.

Why aren't electric motors sold by torque?

Because you can use pullies, sprockets, and gearboxes to get whatever torque you want.

A 1 HP motor running through a 100:1 gear reducer will make more torque than a 50hp motor at 1:1. But obviously the 50hp motor will do more work, even though its output is less torque than the 1hp w/gearbox.

NO IT WOULD NOT! If you could build a gear box big enough to get the thundra to pull that much weight up the hill it would not fit in the truck and the truck would need redesigned just to fit the gearbox. Second the speed it would travel once the gears were reduced in order to make it pull that much weight would make it slower than you can imagine Figure your tractor would be faster in low gear.. Again with your example of the electric motor with a reducer gear to get the power needed to do the work means a reduced speed This is all simple math, pulleys and gears may increase your torque but they also decrease the speed at which the work is done on the other side so the input becomes as important as the outcome. There is no cheating the math it dosnt lie and hasn't changed in such a long time for a reason!

 

[SPYDERLK]

LMAO. You have no idea what you're talking about. A Toyota Tundra can pull more weight than a cement mixer can? That's got to be the silliest statement I've ever seen here. A cement mixer grosses out at around 80K lbs when loaded with 10yds of concrete (yes, that is over legal weight limits). How well would my Tundra pull a total of 80K up a big hill? It probably couldn't do it at all, and if it could, it would be barely moving.

Horsepower is a very poor measure for rating engines, and in fact, is not a legal measure in many countries.

So, your theory is that torque doesn't matter. Okay, I have a simple test for that theory, and you're not going to be able to argue it....sorry in advance.

Take a steam locomotive back in the day. It's at a dead stop. The boiler is fired up, and everything is ready to go. They open the valve to get under way....the pistons aren't turning for that first instant. The engine is making exactly ZERO horsepower (pistons have to move to produce horsepower). How does the train start moving? If it has zero horsepower, how can it move hundreds of tons of weight? How can this be?

The answer is that while the engine is making zero (or very nearly zero until it gets up to full rpm) horsepower, it's making many thousands of ft/lbs of torque.

You are truly the one that has "no idea what you're talking about". ... And I see in some following posts that you have others following this lead. I think you should ask a question that you need an answer to so that knowledgable people dont waste time building from scratch what you should know. We really need a starting point.
larry

 

[sd455dan]

LMAO.
Horsepower is a very poor measure for rating engines, and in fact, is not a legal measure in many countries.

So, your theory is that torque doesn't matter.

Take a steam locomotive back in the day. It's at a dead stop. The boiler is fired up, and everything is ready to go. They open the valve to get under way....the pistons aren't turning for that first instant. The engine is making exactly ZERO horsepower (pistons have to move to produce horsepower). How does the train start moving? If it has zero horsepower, how can it move hundreds of tons of weight? How can this be?

The answer is that while the engine is making zero (or very nearly zero until it gets up to full rpm) horsepower, it's making many thousands of ft/lbs of torque.

Yep that moment of force applied at a distance -(even @ 0 rpm) is Important ...

With tractors I still prefer an engine that extends the highest amount of torque as is possible by design- to the lowest rpm possible (usually just above idle) IMO this makes for a great tractor engine...

 

[SPYDERLK]

With tractors I still prefer an engine that extends the highest amount of torque as is possible by design- to the lowest rpm possible (usually just above idle) IMO this makes for a great tractor engine...

Absolutely. A high fairly flat torque curve with an upward bulge in the mid rpm is great. That way, when youre using peak HP and it lugs down a little the T goes up. Almost like a downgear built in.. Diesels are great at this. ... In general hi compression ratio favors it.
larry

 

[arlen4720]

Absolutely. A high fairly flat torque curve with an upward bulge in the mid rpm is great. That way, when youre using peak HP and it lugs down a little the T goes up. Almost like a downgear built in.. Diesels are great at this. ... In general hi compression ratio favors it.
larry

And diesels continue to inject fuel well into the power stoke.

 

[LD1]

This is all simple math, pulleys and gears may increase your torque but they also decrease the speed at which the work is done on the other side so the input becomes as important as the outcome. There is no cheating the math it dosnt lie and hasn't changed in such a long time for a reason!

You are tight, it is simple math.

While the tundra as a truck might not handle the weight, and would need a total re-design, that is not what we are debating. We are debating HP vs torque. And the engine with the higher HP WILL INDEED get the work done faster. Gearboxes, transmissions, etc were designed to achieve the required torque to do the job. Obviously the tundra in its stock form isnt geard to tow 80k up a hill. BUT....if it were geared properly, it would do it and do so at a faster rate cause it has more HP.

Yes, gearboxes reduce speed while increasing torque. But HP stays the same. And since horsepower is simply a function of work/time, higher HP is faster period.

You can make ANY engine/motor from the smallest known to man to the biggest ever built, move ANY amount of weight, no matter how big or how small. Simply be using gear reducers to achieve the required torque to do the job.

BUT the one with the higher HP will do it faster. I am not saying that torque means absolutely nothing. Obviously you need sufficient torque as to not need a hundred gears. IE: a 80HP 15k rpm crotch rocket engine in lieu of a 80 HP tractor just dont work well as you would need many gears to keep it at its peak.

But I think we can mostly agree that for comparison of various tractors, that they make sufficient torque to do the job and are geared accordingly. HP is what is important on a tractor. Torque is achieved through gearing. A 50HP spinning 3k rpm tractor is going to make MUCH shorter work of bushhogging than a 30HP 2k rpm tractor that might have equal torque or even more.

I personally am able to generate 200+ ft lbs of torque with a simple socket and 18" breaker bar. Do you honestly think I can out-work, or am capable of more work than my tractor that is likely rated in the 80-100ft-lb range. IF that??

You are truly the one that has "no idea what you're talking about". ... And I see in some following posts that you have others following this lead. I think you should ask a question that you need an answer to so that knowledgable people dont waste time building from scratch what you should know. We really need a starting point.
larry

:thumbsup:

 

[LD1]

The relationship between speed, torque, and horsepower is too elementary to even debate.

One would have thought. I dont even know how this got started.

But simply in a practical sense, tractors are similar. At least enough similar in gearing design and engines that torque is of less importance when selecting a tractor than HP. Which is why tractors are spec'd by HP.

 

[arlen4720]

You are tight, it is simple math.

While the tundra as a truck might not handle the weight, and would need a total re-design, that is not what we are debating. We are debating HP vs torque. And the engine with the higher HP WILL INDEED get the work done faster. Gearboxes, transmissions, etc were designed to achieve the required torque to do the job. Obviously the tundra in its stock form isnt geard to tow 80k up a hill. BUT....if it were geared properly, it would do it and do so at a faster rate cause it has more HP.

Yes, gearboxes reduce speed while increasing torque. But HP stays the same. And since horsepower is simply a function of work/time, higher HP is faster period.

You can make ANY engine/motor from the smallest known to man to the biggest ever built, move ANY amount of weight, no matter how big or how small. Simply be using gear reducers to achieve the required torque to do the job.

BUT the one with the higher HP will do it faster. I am not saying that torque means absolutely nothing. Obviously you need sufficient torque as to not need a hundred gears. IE: a 80HP 15k rpm crotch rocket engine in lieu of a 80 HP tractor just dont work well as you would need many gears to keep it at its peak.

But I think we can mostly agree that for comparison of various tractors, that they make sufficient torque to do the job and are geared accordingly. HP is what is important on a tractor. Torque is achieved through gearing. A 50HP spinning 3k rpm tractor is going to make MUCH shorter work of bushhogging than a 30HP 2k rpm tractor that might have equal torque or even more.

I personally am able to generate 200+ ft lbs of torque with a simple socket and 18" breaker bar. Do you honestly think I can out-work, or am capable of more work than my tractor that is likely rated in the 80-100ft-lb range. IF that??




:thumbsup:

As I said before, I think any sufficiently educated person understands that HP (Of an engine) is a function of torque and RPM, and gearboxes change the ratios of speed and torque to suit the application. No ****. That really isn't the debate is it? If so, that debate is for 6th graders. Torque IS very important though, in a practical sense, especially a flat torque curve, for the whole operating experience. You say that the high HP engine will get more work done faster PERIOD. That's not true. An engine with a lower, peakier, torque curve may require allot more shifting than a flatter, less peakier engine. What about clutch wear? What if shifting causes you to lose your momentum? Those are not trivial things.
Go back to my example of a tractor with a 80 hp Japanese motorcycle engine running at 10,000 RPM. How do you think that would work?
I have an x748 diesel lawn tractor, 24 hp. I tried the same tractor with a 25 HP gas engine. The 24hp diesel will run circles around the gas for pulling, mowing and blowing snow. That is because of the flat torque curve of the diesel.

 

[SPYDERLK]

You are tight, it is simple math.

While the tundra as a truck might not handle the weight, and would need a total re-design, that is not what we are debating. We are debating HP vs torque. And the engine with the higher HP WILL INDEED get the work done faster. Gearboxes, transmissions, etc were designed to achieve the required torque to do the job. Obviously the tundra in its stock form isnt geard to tow 80k up a hill. BUT....if it were geared properly, it would do it and do so at a faster rate cause it has more HP.

Yes, gearboxes reduce speed while increasing torque. But HP stays the same. And since horsepower is simply a function of work/time, higher HP is faster period.

You can make ANY engine/motor from the smallest known to man to the biggest ever built, move ANY amount of weight, no matter how big or how small. Simply be using gear reducers to achieve the required torque to do the job.

BUT the one with the higher HP will do it faster. I am not saying that torque means absolutely nothing. Obviously you need sufficient torque as to not need a hundred gears. IE: a 80HP 15k rpm crotch rocket engine in lieu of a 80 HP tractor just dont work well as you would need many gears to keep it at its peak.

But I think we can mostly agree that for comparison of various tractors, that they make sufficient torque to do the job and are geared accordingly. HP is what is important on a tractor. Torque is achieved through gearing. A 50HP spinning 3k rpm tractor is going to make MUCH shorter work of bushhogging than a 30HP 2k rpm tractor that might have equal torque or even more.

I personally am able to generate 200+ ft lbs of torque with a simple socket and 18" breaker bar. Do you honestly think I can out-work, or am capable of more work than my tractor that is likely rated in the 80-100ft-lb range. IF that??

:thumbsup:... At a certain point tho you will forced into stipulating a 100% efficient transmission. Even a simple lever will eventually succomb to losses.
larry