Will 10 Horsepower actually matter on the same size tractor?

[Cahaba Valley Farm]

Haven't read all the posts so someone may have already alluded to this: It seems there will be, if not already, a market for tuning services or kits to take the "same tractor" from, say, 30 to 40 HP. This is very common in the larger tractor and truck arena where chips are available to accomplish.

Now that the Right-To-Repair Act has been signed into law you are probably right.

 

[bearthebruce]

Now that the Right-To-Repair Act has been signed into law you are probably right.

Don't be too sure about this. The Feds have been coming down hard on the tuners because as they tune engines, they often violate the emissions standards bunching the Feds panties. They have already shut down diesel tuning shops.

Right to Repair has nothing to do with "Right to Modify". Right to Repair gives power to fix to the OE spec - not to a new standard.

I believe that if the Enviro people have their way, there will be no more diesels nor any ICE to purchase in 10 years.

Back to the original question - will 10Hp matter? i think so. I would buy as many ponies as I can afford in a tractor. My brush hog bogs down the tractor in heavy grasses. I would like 35hp at the PTO but only have 25hp - barely enough to run the 5 foot Brush Hog in heavy grass. Maybe our next tractor should that day come. We plan to keep our Massey for a long time. No emissions crap on her. Easier to keep her going!

 

[finn1]

On torque rise we should point out that it isn't a matter of which fuel....it makes no difference if it is gas or diesel. Torque characteristics are a function of engine design, not what fuel is used.

Some of the JD two cylinder gas tractors had tremendous torque rise when lugged. Same for some of the other tractors of that era using gas (or LP) industrial engines.

By contrast, our turbocharged Kubota M59 has a wide flat torque response over a wide RPM range, but not much additional torque response to load. I'm guessing that has to do with the EGR emissions tuning.
rScotty

Not exactly. Gasoline engines are throttled to run in a very narrow air/fuel window, usually a little richer than stoic.

Diesel engines run from very lean, at light loads, to a little leaner than stoic along the lug curve. Diesel fuel pumps are calibrated to provide more torque rise than can be achieved with with the constant air fuel ratio gasoline counterpart.

Turbocharged diesels are matched and calibrated to provide much higher torque rise before exceeding smoke limit goals than is achievable with an na engine.

It’s all about combustion chamber design, cylinder head swirl, and fuel system matching.

 

[rScotty]

Have you grooved your r4's? Sounds like it's a nice difference.
That's a great idea to put the front chains on

No, I haven't grooved the R4s. I want the solid rubber for wear because we have a lot of gravel and rocks. And I've never felt the need. From what I see in advertisements, the R14s seem more grooved than the R4s.

Yes, if you are doing beastly work with the tractor - or have a 2wd - then there is a use for rear chains. I've used them for years 40 years ago...
But now being a small landowner just doing our own landscaping and snow removal all we need is a little help from front chains for ice and deep snow. If it steers without sliding, the rest will follow. And it is so much simpler.

rScotty

 

[rScotty]

Not exactly. Gasoline engines are throttled to run in a very narrow air/fuel window, usually a little richer than stoic.

Diesel engines run from very lean, at light loads, to a little leaner than stoic along the lug curve. Diesel fuel pumps are calibrated to provide more torque rise than can be achieved with with the constant air fuel ratio gasoline counterpart.

Turbocharged diesels are matched and calibrated to provide much higher torque rise before exceeding smoke limit goals than is achievable with an na engine.

It’s all about combustion chamber design, cylinder head swirl, and fuel system matching.

Stoic?? That's a word not often used. But if you mean the stoichiometric mix of fuel and air that gives complete combustion, then I don't agree.

We are talking about tractors here - low RPM industrial gasoline tractor engines. Most of them are vintage now. Those gasoline engines are throttled not by changing the mixture but by the mixture volume and velocity. The shape of the venturi within the carb is what keep the mixture "stoic" over their operating range - admittedly this is not a large range.

Mechanical carburation can have a very sharp torque rise because it is simple to hook the main throttle plate to a pressure sensitive governor which gives the motor a near instantaneous response to changes of pressure.

I'd say there are advantages to a gasoline engine's mechanical carburation which are which are hard to match in a diesel without computer control.
rScotty

 

[DerpDerp]

No, I haven't grooved the R4s. I want the solid rubber for wear because we have a lot of gravel and rocks. And I've never felt the need. From what I see in advertisements, the R14s seem more grooved than the R4s.

Yes, if you are doing beastly work with the tractor - or have a 2wd - then there is a use for rear chains. I've used them for years 40 years ago...
But now being a small landowner just doing our own landscaping and snow removal all we need is a little help from front chains for ice and deep snow. If it steers without sliding, the rest will follow. And it is so much simpler.

rScotty

Thats cool, do you get pretty serious snow there, say like 12" or 16" at a time?
Do you run ballast or have the rears loaded? Are you pushing or blowing?
It's interesting how mixed everyone's opinions and experiences can be with the same tires ya know?

 

[finn1]

Stoic?? That's a word not often used. But if you mean the stoichiometric mix of fuel and air that gives complete combustion, then I don't agree.

We are talking about tractors here - low RPM industrial gasoline tractor engines. Most of them are vintage now. Those gasoline engines are throttled not by changing the mixture but by the mixture volume and velocity. The shape of the venturi within the carb is what keep the mixture "stoic" over their operating range - admittedly this is not a large range.

Mechanical carburation can have a very sharp torque rise because it is simple to hook the main throttle plate to a pressure sensitive governor which gives the motor a near instantaneous response to changes of pressure.

I'd say there are advantages to a gasoline engine's mechanical carburation which are which are hard to match in a diesel without computer control.
rScotty

Not sure what you don’t understand about combustion. Otto cycle engines run within a narrow a/f ratio band, on the rich side of stoichiometry (sorry if you didn’t understand the common shortening of the word as used by engine people

The engine is throttled to maintain this a/f ratio across the bmep map. A gas engine won’t run at 25:1 let alone at 100:1.

Show me a gasoline engine with 25% torque rise between rated speed/load and peak torque. Hint: you won’t find any.

On reflection, it sounds like you don’t understand what torque rise is. It’s the percentage increase in torque when an engine is running at full power, rated speed, and additional load is added to lug the engine to the point maximum torque output is observed.

what you are describing is called governor regulation. Operate the engine at a given speed, no load, then add load until you reach the lug line. The steepness of the rpm vs torque line is regulation. Targets is usually in the 10%-12% range, although combines are usually tighter, with 3%, and the goal for generators is often isochronous governing.

 

[Cahaba Valley Farm]

Turbocharged diesels are matched and calibrated to provide much higher torque rise before exceeding smoke limit goals than is achievable with an na engine.

I can't think of a better match made in heaven then a diesel engine and a turbo charger.

 

[Cahaba Valley Farm]

Not sure what you don’t understand about combustion. Otto cycle engines run within a narrow a/f ratio band, on the rich side of stoichiometry (sorry if you didn’t understand the common shortening of the word as used by engine people

The engine is throttled to maintain this a/f ratio across the bmep map. A gas engine won’t run at 25:1 let alone at 100:1.

Show me a gasoline engine with 25% torque rise between rated speed/load and peak torque. Hint: you won’t find any.

On reflection, it sounds like you don’t understand what torque rise is. It’s the percentage increase in torque when an engine is running at full power, rated speed, and additional load is added to lug the engine to the point maximum torque output is observed.

what you are describing is called governor regulation. Operate the engine at a given speed, no load, then add load until you reach the lug line. The steepness of the rpm vs torque line is regulation. Targets is usually in the 10%-12% range, although combines are usually tighter, with 3%, and the goal for generators is often isochronous governing.

Ah yes, a good debate about things that are going way over my head. Maybe I will learn a thing or two from this. Data Pipe GIF - Data Pipe Thinking - Discover & Share GIFs

 

[rjpotts]

But where would one measure torque?

At the engine? Lets say one tractor has 100ft-lbs and another of similar size has 150ft lbs. Is it really better? Transmission gearing, rear axle gearing, PTO gearing....all changes torque. Gearing does not change HP (except for inefficiencies like friction losses).

And torque still has no time element. I dont understand why so many think HP isnt a good number to compare. Horsepower is simply how much torque can be applied in a given time. So if you like torque so much....and hate comparing HP....is it the time element you hate so much?

One HP (think one working horse) is only capable of so much in a given day. But that same horse can generate anywhere for 1ft-lb of torque or 10,000ft lbs of torque. Just depends on how big of a lever or how many pulleys on a snatch block to gain mechanical advantage. But at the end of the day, its still only ONE HP.

Ram pickup engines.

6.4 L gas has 410 HP and 422 ft/lb torque.

6.7 diesel has 370 hp and 850 ft/lb torque.

The diesel has higher towing capacity even though it has less HP.