best operating RPM?

[Reg]

Quote:
Originally Posted by Opti-Mist
The worst thing to do to a tractor is "baby" it. The engine is designed to "work" and light loads are undesirable and result in things like oil consumption and blow by as rings don't seat, etc. On the other hand, one does not want to lug the engine either.




It's only a misconception in your view. Operating a diesel at low ERPMs doesn't allow the engine to reach operating temperature. A cold diesel is an inefficient one, leading to more combustion residue in the crankcase oil and unburnt fuel coating and perhaps eventually plugging the exhaust system. As Opti-Mist says, piston rings won't seat properly under light load/low temp/low ERPM. Hydrostatic transmissions suffer at low input RPMs because charge pressures can be low, oil flow to the oil cooler can be diminished, and the transmission's ability to transmit torque at low input speeds is a fraction of what it would be at rated speed. Consequently, hydrostatic oil temperatures can actually be higher than normal in this scenario. You may think you are doing yourself and your tractor a favor, but actually you are risking killing it with kindness. If you can run your tractor's cooling system between 180 and 210 or so, and keep clean engine oil in it, it's pretty hard to hurt the engine. A steady diet of cold engine is just as lethal as overheating, just slower.

Then I suggest you consult for the auto and truck manufacturers.
They would just LOVE TO KNOW that diesel engines in cars and trucks NEED to be run in the lowest possible gear to keep the revs up and "seat piston rings properly".
Do you have ANY IDEA what the cylinder pressure difference is between idle and max revs ?
and what difference that makes to "ring seating" ?
{quantitatively}

The auto trannie shift algorithm is biased toward keeping the engine at the minimum revs that will do the job - I guess that is "WRONG" by your logic ?
Some folk in Detroit need to hear from you, maybe that is why they went broke, help 'em out will Ya ?

Hey, I drive in traffic, the truck idles, sometimes for longer than I actually USE my tractor.
Would you have me apply the brake and step on the accelerator JUST to keep the engine block warm and happy ?

and you will argue that tractor diesels are different, HOW ?

 

[AndyMA]

On my Ford 2120 540 PTO speed is called "fast idle" Tractor engines are designed to run wide open full time. The so called "sweet spot" is probably a function of exhaust and combustion chamber resonate frequencies.

Amdy

 

[dave1949]

I seem to spend a lot of time running around 1750 rpm for FEL work and transport. When running the bush hog, then I bring the engine speed up to around 2200 rpm. Using the backhoe usually around 2000-2100 rpm.
Dave.

 

[Opti-Mist]

Yes, Reg, they are different by design. Tractor engines are designed as low speed high torque engines. Automotive diesels are higher revving by design so they will work with automatic transmissions which can also be used with gas engines. There is also a question of mass. Tractor engines are more massive by design to serve the application, they also serve as a structural component of the vehicle (generally no frame). Automotive diesels are lighter for fuel efficiency reasons.

 

[Reg]

Yes, Reg, they are different by design. Tractor engines are designed as low speed high torque engines. Automotive diesels are higher revving by design so they will work with automatic transmissions which can also be used with gas engines. There is also a question of mass. Tractor engines are more massive by design to serve the application. Automotive diesels are lighter for fuel efficiency reasons.

My truck isn't a high revving diesel, it idles lower than any tractor I've ever had and it red lines about where a lot of tractors have their 540 PTO mark on the tach.
It is doing just about 2,000 rpm at highway speeds, hardly a high revving engine.

You might be thinking small car diesels, the VWs diesels CAN rev.
Other than being fairly conservatively rated for their displacement, there is nothing "by design" in a tractor's diesel that requires it to be run any faster than any other diesel, automotive, marine, stationary, etc.
Ooops, Marine is different - wish I hadn't brought THAT up (-:

 

[Hematite]

I seem to spend a lot of time running around 1750 rpm for FEL work and transport. When running the bush hog, then I bring the engine speed up to around 2200 rpm. Using the backhoe usually around 2000-2100 rpm.
Dave.

Those are pretty much the speeds that I run the tractor at.

 

[Opti-Mist]

Reg, take a look at the torque and horsepower curves. That should show where the ability to do work is in terms of engine rpms.

 

[RickB]

Then I suggest you consult for the auto and truck manufacturers.
They would just LOVE TO KNOW that diesel engines in cars and trucks NEED to be run in the lowest possible gear to keep the revs up and "seat piston rings properly".
Do you have ANY IDEA what the cylinder pressure difference is between idle and max revs ?
and what difference that makes to "ring seating" ?
{quantitatively}

The auto trannie shift algorithm is biased toward keeping the engine at the minimum revs that will do the job - I guess that is "WRONG" by your logic ?
Some folk in Detroit need to hear from you, maybe that is why they went broke, help 'em out will Ya ?

Hey, I drive in traffic, the truck idles, sometimes for longer than I actually USE my tractor.
Would you have me apply the brake and step on the accelerator JUST to keep the engine block warm and happy ?

and you will argue that tractor diesels are different, HOW ?

This isn't about autos and trucks, and tractors don't have automatic transmissions.
I don't come here to argue. You have read my thoughts.
Enjoy your tractor.

 

[JC-jetro]

just my 2 cents here,

As one old sage told me long time ago, "You know what ?" and I replied "what?" and he said " Opinions are like xxx-hole and we all sure have one". I told him "Wow .. what a revelation!!". It is a good thing to come here and learn from people's experiences, opinions, ideas and many other things. No sense in getting bent out of shape just because someone things a bit differently.

Everyone has a choice to pick up what is useful to them and leave the rest behind.

JC

 

[RickB]

just my 2 cents here,

As one old sage told me long time ago, "You know what ?" and I replied "what?" and he said " Opinions are like xxx-hole and we all sure have one". I told him "Wow .. what a revelation!!". It is a good thing to come here and learn from people's experiences, opinions, ideas and many other things. No sense in getting bent out of shape just because someone things a bit differently.

Everyone has a choice to pick up what is useful to them and leave the rest behind.

JC

It's also a proven fact that some opinions are bigger than others.