HST Engine RPM
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veresjwv
Silver Member
I like SET HIGH AND FORGET... After operating my L3400 loader and various other operations there is almost a "sweet spot" on the throttle that happens to be around 1700 to 2000 RPMs. This is when I get good hydraulic flow and good fuel economy and the engine sounds like that is where it wants to be.
PTO - I always run on the 540 mark or higher.
mwb
Platinum Member
Lugging the engine also causes low engine oil pressure = wear. If it is lugging then the engine is under heavy load and it is not able to get the oil pressures up (flow).
If I am not under load (cruising around) I run mine at 1500; I think 2200 is 540PTO, 2500 is red line. I don't like to run "all out" unless I am into some serious loader or PTO work. If my HST feels like it's unhappy (excessive whine or the cavitation feel, then up the RPM's, shift to lower range.
Anytime someone else drives my machine I show them the pedals (fwd, rev) and say to put the tach on 1500. I don't let anyone work the machine.
If I am not under load (cruising around) I run mine at 1500; I think 2200 is 540PTO, 2500 is red line. I don't like to run "all out" unless I am into some serious loader or PTO work. If my HST feels like it's unhappy (excessive whine or the cavitation feel, then up the RPM's, shift to lower range.
Anytime someone else drives my machine I show them the pedals (fwd, rev) and say to put the tach on 1500. I don't let anyone work the machine.
Larry Caldwell
Elite Member
It's better to back off on the RPMs and run the HST pedal down. If mid range requires a light tough on the pedal, shift down to low and stomp on it. The higher oil flow volume will run through the oil cooler faster and keep the whole transmission cooler. A lower gear also reduces the strain on the wobble pump, hydraulic motors and gearing.
As far as the engine is concerned, NEVER lug a diesel. You will hammer the rod bearings right off the crank shaft. Run the engine fast enough to generate enough horsepower to do the work. Anything past that is overkill. Full RPM on my L3130 is about 2600 RPM, but when I'm doing loader work I often run it around 1800.
TalonDancer
Gold Member
- Joined
- Jul 29, 2007
- Messages
- 388
Out of curiosity, have any of you who regularly run at over 1,800 RPM for FEL or back hoe work actually tried doing the same thing at say 12-1400 RPM? For example, have you loaded your FEL to the point that it won't lift the load and then removed just enough material that it can barely lift the load at say 1,200 RPM then cranked up the engine to say 2,000 RPM to see how much higher it will lift the load?
FWIW on my L3240 the answer is -- not very much. Once the engine RPM is above 1,200 RPM the difference in lift is so small as to be negligible. I might be able to squeeze a few inches more lift with the engine wailing. But the difference is so small that I'd rather just remove some material. OTOH the FEL moves more quickly. So I often use the hand throttle to temporarily increase the RPM while lifting or curling the bucket before trundling off using Auto Throttle and keeping the RPM's down. The same applies to my BH90. Above 1.200 RPM increasing the RPM only increases the SPEED of operation. It does NOT increase the POWER of the back-hoe. IOW if my BH90 won't bust a large rock out of the trench at 1,200 RPM, it won't do it at 2,000 RPM either. But it will swing the bucket out of the trench quicker
Talon Dancer
FWIW on my L3240 the answer is -- not very much. Once the engine RPM is above 1,200 RPM the difference in lift is so small as to be negligible. I might be able to squeeze a few inches more lift with the engine wailing. But the difference is so small that I'd rather just remove some material. OTOH the FEL moves more quickly. So I often use the hand throttle to temporarily increase the RPM while lifting or curling the bucket before trundling off using Auto Throttle and keeping the RPM's down. The same applies to my BH90. Above 1.200 RPM increasing the RPM only increases the SPEED of operation. It does NOT increase the POWER of the back-hoe. IOW if my BH90 won't bust a large rock out of the trench at 1,200 RPM, it won't do it at 2,000 RPM either. But it will swing the bucket out of the trench quicker
Talon Dancer
Out of curiosity, have any of you who regularly run at over 1,800 RPM for FEL or back hoe work actually tried doing the same thing at say 12-1400 RPM? For example, have you loaded your FEL to the point that it won't lift the load and then removed just enough material that it can barely lift the load at say 1,200 RPM then cranked up the engine to say 2,000 RPM to see how much higher it will lift the load?
FWIW on my L3240 the answer is -- not very much. Once the engine RPM is above 1,200 RPM the difference in lift is so small as to be negligible. I might be able to squeeze a few inches more lift with the engine wailing. But the difference is so small that I'd rather just remove some material. OTOH the FEL moves more quickly. So I often use the hand throttle to temporarily increase the RPM while lifting or curling the bucket before trundling off using Auto Throttle and keeping the RPM's down. The same applies to my BH90. Above 1.200 RPM increasing the RPM only increases the SPEED of operation. It does NOT increase the POWER of the back-hoe. IOW if my BH90 won't bust a large rock out of the trench at 1,200 RPM, it won't do it at 2,000 RPM either. But it will swing the bucket out of the trench quicker
Talon Dancer
Interesting info, I`ll test my new tractor and report back.
I know with my rental if I didn't have the RPMS high it wouldn't make it up the small hills on my property, and even at full RPM a full bucket of dirt could barely 'break-out' of my LOOSE dirt pile I made the same day. As I've noted in other threads I think they had the hydraulic pressure lower, or some other issue. :confused2: so I don't thnk that's standard. (40hp new Holland)
TalonDancer
Gold Member
- Joined
- Jul 29, 2007
- Messages
- 388
BTW my comments had to do with just the FEL and BH hydraulics. My L3240 HST + requires nearly full RPM to go up some of the steeper sections of our driveway. And even then it loses quite a bit of ground speed.
I run with the HST + Auto Throttle ON all the time and have moved a lot of heavy pallets (e.g. 3/4 ton). I get to see the difference in engine RPM needed to do the actual lifting vs moving the tractor + load every time. Picking up a heavy pallet requires coming to a full stop which drops the engine RPM to idle. So unless I use the hand throttle, the first part of the lift is done with the engine at 900 RPM. I only use the hand throttle on the heaviest pallets.
Talon Dancer
Kubota-guy1911
Silver Member
- Joined
- Oct 18, 2008
- Messages
- 152
- Location
- Glenarm, IL.
- Tractor
- Kubota L2501, Kubota BX2350, IH Cub Cadet 1450, Cub Cadet (Diesel) 1572
Just keep in mind the drive shaft off the engine is direct drive for the hydro cooling fan. If you're working the hydraulics long and hard I would want lots of air flow back there.
kj
kj
