Snowblower PTO & Engine Speed

[TimP]

Hi All. I have read a few threads about this but am still looking for more info.

I have a B2150 and a rear 3PH snowblower which runs at 540 PTO RPMs.

I have two PTO speed settings on the B2150... 540 and 780.

The engine speed setting for the 540 PTO RPMs is 2500.

Exactly why can't I put my PTO in it's 780 gear and run the engine at 1250 if that produces a PTO RPM of 540 ?

It will be less stressful on the engine and save fuel.

Is it because of less torque at the 780 setting as opposed to the 540 setting on the PTO ?

The blower won't care as long as I don't exceed the 540 RPMs at the PTO correct ?

Is it just too stressful for the engine or PTO gears ?

Thanks.

 

[BeezFun]

Check your math, I think you want to run it at 1730 to get 540rpm on the 780 setting. I don't see any reason to not do that, you might find you don't have enough torque. If that's the case go back to running the engine faster.

 

[TimP]

Check your math, I think you want to run it at 1730 to get 540rpm on the 780 setting. I don't see any reason to not do that, you might find you don't have enough torque. If that's the case go back to running the engine faster.

I was surely having a senior moment with the Math...... I'll take your word for it. 1730 it is and I'll give it a try during the next "big" snow in Baltimore.

The last one we got was supposed to be 10"-12" and ended being only 4" at my house.

Not worth the effort to mount the snowblower, I should have just left the blade on the tractor. But if I didn't put the blower on, for sure it would have dumped 12" on us.

Thanks for the info... I appreciate it.

Regards......

 

[AStanton]

My B3030 has an idiot mark on the tach for 540. I don't see where you would get a choice.

 

[Marveltone]

Running PTO equipment at lower RPM to save on wear and tear makes no sense to me. The PTO/RPM speed is generally set at a point where the engine can work under heavy load for prolonged periods of time. It's usually at or near where the engine makes the most usable power and cools most efficiently. Remember, when you slow down the engine you also slow down the water pump and the fan. Engines need to be cooled, especially under heavy load. My guess is the engineers had a pretty good idea what they were doing. I'll run my tractors around at lower RPM if it's just light running around, but as soon as the workload increases, or a PTO implement is engaged, the RPM is increased to match. Diesels don't like to be lugged.

Just my :2cents:

Joe

 

[TimP]

My B3030 has an idiot mark on the tach for 540. I don't see where you would get a choice.

The B2150 has a mark for 540 as well at 2500 RPM's, but no mark for 780. I "Assume" the gearing is such that the same engine rpm gives the PTO 780 RPMs when the PTO speed selection lever is set in the 780 position.

 

[TimP]

Running PTO equipment at lower RPM to save on wear and tear makes no sense to me. The PTO/RPM speed is generally set at a point where the engine can work under heavy load for prolonged periods of time. It's usually at or near where the engine makes the most usable power and cools most efficiently. Remember, when you slow down the engine you also slow down the water pump and the fan. Engines need to be cooled, especially under heavy load. My guess is the engineers had a pretty good idea what they were doing. I'll run my tractors around at lower RPM if it's just light running around, but as soon as the workload increases, or a PTO implement is engaged, the RPM is increased to match. Diesels don't like to be lugged.

Just my :2cents:

Joe

Makes a lot of sense to me. When I was blowing yesterday, the outside temp was 10 degrees, so overheating wasn't much of a concern. I'll try running with the PTO set at 780 and see if the engine seems to get overloaded or if the temp ever gets higher than it should.

Thanks !

 

[Mendonsy]

I have been doing that with my B7500 for years. It has a 900 RPM speed which works fine with everything at 1500 engine RPM.
When I need more power (seldom) I use the regular 540 RPM setting.