Tractor classification — HP vs torque

[domains]

torque longer compression stroke, shorter rod more RPM

 

[LD1]

torque longer compression stroke, shorter rod more RPM

Rod length doesnt change the stroke

 

[K5lwq]

That’s what she said.

 

[Tinhack]

Back in my racing days it was torque that got you there, but it was horsepower that kept you there. I mean first place, that is.

 

[domains]

On a 4 stroke leave the motor stock if you place a turbo, if you want it to last, Id rather bigbore and play with compression ratio

 

[mapper]

Some of the discussion here is more about reliability vs efficiency. You can push a small displacement engine to really high hp, example - F1 race cars making 1000 hp+ from a 1.5 liter 4 cylinder engine vs a tractor with a 6+ liter engine making 150 to 200 hp. The F1 engine is going to last about 500 miles at 150 mph (<6 hours) before needing a major overhaul, where the tractor engine will last 10,000 hr at least before needing repairs.

 

[LouNY]

A torque master;
600 Horsepower Snow Gas Engine

Now this is an engine, be a bit tight fitting in a tractor but,

This engine was manufactured by the Snow-Holly Works of Buffalo, New York, and is serial number G329. It has two tandem 24-inch bore x 48-inch stroke cylinders that are double-acting. Fuel for the engine is natural gas with make and break igniters providing ignition. Total displacement is 86,800 cubic inches or 1,423 liters. The rated output of the engine is 600 hp at 100 RPM, which yields a torque value of 31,500 ft-lbf.

 

[domains]

I placed a XR650L motor on a 400ex frame, bigbore 680, 720 Max bore is the sweet spot but need to hone cases for the bore to fit, You can 830 but need to beef up the crank case and its aluminum.

I stayed at 680 because I didn't like the compression ratio of the 720 piston options

Used dom steal to build the drag bars, and placed one behind motor

Need a oil rad cooler and place oil tank infront of it, Drill a hole in dip stick and place a cooking digital temp gauge , JB weld it

If you port the intakes to much you will lose vacuum, Some even JB the intake ports smaller for more vacuum, Or you can weld and grind it. I left it stock and 220 sand paper, plus placed carb boot on and matched it, I bought the 1988 boot to pull carb further from motor but had more hp with the stock one because its on an angle and the gas spins while entering the combustion cycle.

Get a honda civic after market K&N filter and aluminum pipe or none and raise the main jet if only dragging

The xr650r chrome sleeve motors have a nice carb that changing the main jet only takes a few mins and no need to take off motor.

I'l try to find a pic of it later
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Heres the hard to find piston if interested, you will need the 720 sleeve and hone base so sleeve is thick , but if only for dragging all you will need is the piston, this one is only +1.00 mm so stock sleeve will be ok, 102.41 is the piston I used if you can find it.

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Make sure you jet it right, New spark plug or clean old, Race it though all gears, stop and check color, looking for brown paper bag color, I used gsxr1100 dual pipes and cuplings with springs .good luck

 

[WinterDeere]

A torque master;
600 Horsepower Snow Gas Engine

You'd need a friend just to tell you what's in your loader bucket, if you ever built a tractor around that engine.

 

[S854]

This here illustrates how higher HP will get the job done faster but torque will get more work done…

 

[LD1]

This here illustrates how higher HP will get the job done faster but torque will get more work done…

Thats not an illustration of torque. Its weight/traction......and dont even look like they had weight on the sled.

 

[Chewwy]

Interesting video but it does nothing to prove the claim that “torque gets more work done.”

 

[S854]

I still don’t get it… I once had a (roughly) 110 HP BMW 2002tii… the car was quick, handled well and was an absolute ball to drive…

However, that cars engine didn’t have any hope to be able to move that CASE an inch… let alone the sled (weighted or not)

 

[Chewwy]

I still don’t get it… I once had a (roughly) 110 HP BMW 2002tii… the car was quick, handled well and was an absolute ball to drive…

However, that cars engine didn’t have any hope to be able to move that CASE an inch… let alone the sled (weighted or not)

Sorry you don’t get it.

Properly geared the 110 hp engine could move the Case just fine, but likely not very fast. Torque can be mutipled via gearing. HP cannot be multiplied by gear ratios.

 

[S854]

I’m just gonna wash out my brain, forget this whole “HP vs torque” thing and enjoy my tractor…

Probably better this way…

 

[etpm]

I wonder just how true HP figures are. I have a JD riding mower with a 24 HP Kohler engine. I have a Yanmar YM23210 tractor with either a 23 HP engine or a 27 HP engine. I'm not sure which because I have seen specs both ways. But even if it has a 27 HP engine my tractor will way out perform the JD pulling something at the same speed. Better than twice as good and 3 HP wouldn't account for the difference. And my tractor weighs a whole lot more than the riding mower. I believe the HP spec for my tractor but not the one for the JD.
Eric

 

[Chewwy]

I wonder just how true HP figures are. I have a JD riding mower with a 24 HP Kohler engine. I have a Yanmar YM23210 tractor with either a 23 HP engine or a 27 HP engine. I'm not sure which because I have seen specs both ways. But even if it has a 27 HP engine my tractor will way out perform the JD pulling something at the same speed. Better than twice as good and 3 HP wouldn't account for the difference. And my tractor weighs a whole lot more than the riding mower. I believe the HP spec for my tractor but not the one for the JD.
Eric

I assume your JD Riding mower is gas powered and your Yanmar tractor is diesel powered. Their operating characteristics are significantly different.

Look at the typical torque/hp vs speed curve for both gas and diesel engines. Diesel engines typically develop peak torque at low rpm that is well below the rpm for peak hp. Gas engines typically develop both peak torque and hp at significantly higher rpms.

 

[WinterDeere]

I still don’t get it… I once had a (roughly) 110 HP BMW 2002tii… the car was quick, handled well and was an absolute ball to drive…

However, that cars engine didn’t have any hope to be able to move that CASE an inch… let alone the sled (weighted or not)

What is the BMW's ground speed at 2500 RPM in its lowest gear? Now compare that to your tractor at 2500 RPM in its lowest gear.

Does that clear it up?

I wonder just how true HP figures are. I have a JD riding mower with a 24 HP Kohler engine. I have a Yanmar YM23210 tractor with either a 23 HP engine or a 27 HP engine. I'm not sure which because I have seen specs both ways. But even if it has a 27 HP engine my tractor will way out perform the JD pulling something at the same speed.

As already noted, different power curves, which results in different torque at each RPM. Also, there are multiple methods by which horsepower can be measured, all valid, but with different caveats and results.

 

[etpm]

I assume your JD Riding mower is gas powered and your Yanmar tractor is diesel powered. Their operating characteristics are significantly different.

Look at the typical torque/hp vs speed curve for both gas and diesel engines. Diesel engines typically develop peak torque at low rpm that is well below the rpm for peak hp. Gas engines typically develop both peak torque and hp at significantly higher rpms.

Yeah, I understand the torque differences. It doesn't matter where the rpm is. The JD doesn't come close in pulling power. I set the JD throttle high and use the HST pedal for low speed. This should give me the best pulling power. Yet the engine lugs down way before the engine in the Yanmar. The JD just cannot pull near the load without the engine lugging way down that the Yanmar can. I think either Kohler is overstating HP figures or Yanmar is wildly understating the HP output of their engines. I don't have a dyno and so can't test the engines that way. So I really don't know how much HP I am getting at the rear wheels.
Eric

 

[Chewwy]

Yeah, I understand the torque differences. It doesn't matter where the rpm is. The JD doesn't come close in pulling power. I set the JD throttle high and use the HST pedal for low speed. This should give me the best pulling power. Yet the engine lugs down way before the engine in the Yanmar. The JD just cannot pull near the load without the engine lugging way down that the Yanmar can. I think either Kohler is overstating HP figures or Yanmar is wildly understating the HP output of their engines. I don't have a dyno and so can't test the engines that way. So I really don't know how much HP I am getting at the rear wheels.
Eric

Thats the difference between the performance of diesels and gas engines. Diesels when loaded drop in rpm but the available torque increases with that drop in rpm. Gas engines just drop in rpm and also drop the available torque.