Engine RPM vs. performance vs. engine wear

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500K_773

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Mar 5, 2004
Messages
342

I was looking over Kubota engine specs and found the torque and horsepower charts interesting. My 773 has the V2003TE engine making a peak HP of 56 with a torque of 106 ft.lbs. at 2800 RPM. The max engine torque of 121 ft.lbs. is made at ~1700 RPMs at 38 HP. I normally run the engine at 2650-2700 RPM to help conserve fuel and reduce engine wear, but could probably run at 2550-2600 RPM without much loss of performance.

The V3300TE engine used in larger machines makes a peak HP of 83 HP and ~170 ft.lbs. of torque at 2600 RPM. Max engine torque of ~210 ft.lbs. of torque is made at ~1575 RPM at ~58 HP.

I know the hydraulic pump most likely makes the most power (flow and pressure) available from the highest RPMs possible, but the engine should work best at it’s peak torque RPM (most force available to do the work). It looks like pressure and power from the hydraulic pump have linear increases, which correspond directly to increased RPM. Since the skidsteer loaders are hydrostatic drive and have hydraulic attachments, they would benefit most from increased flow and pressure of the higher RPM.

What RPMs does everyone else run their machine at? If lower than max RPMs, please state how much lower because each engine has a different max RPM.
Do you think running at lower RPMs will decrease wear on your engine and extend the life?
Is it OK to run at max engine RPMs all the time?
 

Team Fountain

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Mar 16, 2004
Messages
61
I run at max RPM. The machine seems to move smoother and the dealer says full throttle full time - of course he's in the business of selling new machines. :eek:] I don't think its any easier on the engine to run at a decreased RPM. In fact, I think the opposite. It's much harder on the engine to stall it from lack of rpm than to run it at a constant higher r. Lets face facts, how often does one of these little kubota engines fail. Not very often around here. I think pre mature failure has a lot more to do with lack of maintenance than what r u run it at. JMO.
 

500K_773

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Joined
Mar 5, 2004
Messages
342
You might want to be careful about running the engine at a lower RPM; it might not get you better performance. The peak torque may come at 1700 RPM, but the power or torque bulges may come at the 56 horsepower region. Therefore, although you get more initial "oomph," the engine may bog down slower. Bobcat factory reps might be able to be of more help on where the exact bulges occur.
 

500K_773

Well-known member
Joined
Mar 5, 2004
Messages
342
You might want to be careful about running the engine at a lower RPM; it might not get you better performance. The peak torque may come at 1700 RPM, but the power or torque bulges may come at the 56 horsepower region. Therefore, although you get more initial "oomph," the engine may bog down slower. Bobcat factory reps might be able to be of more help on where the exact bulges occur.
I wasn't planning on running it at such a low RPM, just thought that since the most torque was made there it would make sense that the engine would be least likely to stall. But that would be in a direct drive application, not a hyrostatic drive application like a skidsteer.
The horsepower curves flattened out in both engines about 200 RPM from max, so I was thinking that running the engine a couple of hundred RPM below max would reduce some engine wear and fuel consumption. In fact, one of the mechanics and the dealership told me there was no need to run it at max, just a couple of hundred RPM below max. I have a tendancy to my just about max anyway because during the course of the day, the engine bleeds off about 50-75 RPM, I think the throttle lever may vibrated back a little.
 
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