WOT on diesel tractors

[Coyote machine]

Some here claim WOT or nothing. So prove it by concrete evidence from written statements from the various manufacturers you insist require WOT at all times. Otherwise do what you want with YOUR tractor and the rest of us will do what we see as conscientious with ours.

 

[Gale Hawkins]

In my mind WOT on a farm tractor is the RPM that gives the PTO speed of 540/1000 RPM. The maker designed it to run at that engine speed 24/7. The only time I ever saw my dad override this rule of his was if he got stuck and was trying to rock it out in a higher gear after backing up as far as it would move.

 

[Gary Fowler]

I see that most of you are missing the most important detail here. When using your hydraulic, unless your pump is drastically undersized, you rarely need full flow to make it work at the fastest speed that the hydraulic lines can handle. Most tractors unless the pumps are worn out or nearly so, will reach max pressure at 50% throttle or less. I have had a gauge on my B26 and it produces full pressure at just above idle (1200 RPM but not full flow. You can only get so much flow thru a 1/2" hydraulic tubing line to any particular valve so having 16 GPM flowing via WOT wont make the cylinder move any faster. At the point where you reach max flow and the pump goes into by-pass is the max speed you have to run to reach maximum production. Any more throttle and you are just wasting fuel. Each piece of equipment will reach this point at a different engine speed depending on the pump and its efficiency.
There is a big difference in "NEEDING TO RUN WOT TO PREVENT DAMAGE" AND "NEEDING TO RUN WOT TO MAKE PRODUCTION". The original poster's comments was that if you didn't run WOT you would damage your machine and that statement IS total BS.

You guys can continue to argue personal preferences for days on end but you wont find any machines damaged from running less than WOT as long as they aren't lugging the engine. Throttle setting is there for a reason, so you the operator can adjust it to suit the task.

Running WOT is not going to hurt the tractor engine or pump because they are designed to do so, but running less than WOT is not going to hurt it either

 

[Gale Hawkins]

Good point Gary at least on our old worn out 1983 JD 310B backhoe. 30 years later I find its break out ability is about the same at 1200 as 2400 RPM when digging but with much less than half of the sound level.

75% of absolute max RPM of an engine is about all I care to do in a geared tractor. I know the hydrostatic machines are a different animal but not from personal experience.

 

[Coyote machine]

In my mind WOT on a farm tractor is the RPM that gives the PTO speed of 540/1000 RPM. The maker designed it to run at that engine speed 24/7. The only time I ever saw my dad override this rule of his was if he got stuck and was trying to rock it out in a higher gear after backing up as far as it would move.

Just because a machine CAN run at WOT all the time does NOT mean it has to or needs to for ALL tasks for which it is used.

 

[TripleR]

I don't know enough to argue one way or the other, but I think someone already mention the John Deere EPTO, can't see them offering an option that will cause harm to the tractor, maybe I am missing something.

 

[Coyote machine]

I see that most of you are missing the most important detail here. When using your hydraulic, unless your pump is drastically undersized, you rarely need full flow to make it work at the fastest speed that the hydraulic lines can handle. Most tractors unless the pumps are worn out or nearly so, will reach max pressure at 50% throttle or less. I have had a gauge on my B26 and it produces full pressure at just above idle (1200 RPM but not full flow. You can only get so much flow thru a 1/2" hydraulic tubing line to any particular valve so having 16 GPM flowing via WOT wont make the cylinder move any faster. At the point where you reach max flow and the pump goes into by-pass is the max speed you have to run to reach maximum production. Any more throttle and you are just wasting fuel. Each piece of equipment will reach this point at a different engine speed depending on the pump and its efficiency.
There is a big difference in "NEEDING TO RUN WOT TO PREVENT DAMAGE" AND "NEEDING TO RUN WOT TO MAKE PRODUCTION". The original poster's comments was that if you didn't run WOT you would damage your machine and that statement IS total BS.

You guys can continue to argue personal preferences for days on end but you wont find any machines damaged from running less than WOT as long as they aren't lugging the engine. Throttle setting is there for a reason, so you the operator can adjust it to suit the task.

Running WOT is not going to hurt the tractor engine or pump because they are designed to do so, but running less than WOT is not going to hurt it either

Agreed. Put another way; if all the HST tractors were meant to ONLY be run at WOT then why complicate them with throttles? Just one speed- WOT, no throttle or any speed adjustment under any circumstances; just a light switch; WOT or OFF.
Case closed. Next argument.

 

[arlen4720]

Agreed. Put another way; if all the HST tractors were meant to ONLY be run at WOT then why complicate them with throttles? Just one speed- WOT, no throttle or any speed adjustment under any circumstances; just a light switch; WOT or OFF.
Case closed. Next argument.

and why would they put ePTO's on them...a mode where the engine is actually limited to 1750 RPM (on a 4x20).

 

[SPYDERLK]

Agreed. Put another way; if all the HST tractors were meant to ONLY be run at WOT then why complicate them with throttles? Just one speed- WOT, no throttle or any speed adjustment under any circumstances; just a light switch; WOT or OFF.
Case closed. Next argument.

Really? ... You would close the case on starts of a cold engine/hyd system. :confused2:

 

[buickanddeere]

Just to be clear

#1 if the hydraulic load needs eg 10gpm and the tractor's pump will flow 25gpm at redline. The running the engine at 45-50% of redline rpms is fine.
#2 Some Bubba that has a tractor with a 2400rpm redline and is field ploughing with the throttle at 1/2 and rpms at 1200 with smoke billowing from the stack as the engine luggs. Bubba isn't too swift and is causing extra wear on his tractor's engine and drive train.

For loader work unlike my Uncle who owned the tractor before myself and smoked the clutch at less than 2000hrs. I set the hand throttle to approx 1000rpm and use the foot throttle to speed up once the clutch is engaged . Uncle would leave the revs at 2200 and slip the clutch to vary ground speed. His previous tractor had neither foot throttle or a differential lock. Not a lick of wear on the paint on either pedal when I bought the tractor. If spinning he would jam the brakes on the spinning wheel.
Ploughing, V-ripping or other heavy tillage and working hard. The throttle is at or near WOT.
Running the pto generator? You can bet the rpms are at 540 and verified to be 60Hz with an electrical meter. I've seen and heard tell from generator shops about operators who throttled back generators to "save" money. Proof that electricity is actually smoke that travels inside the wires.Make a mistake, the smoke leaks out and the device no longer works.