Biggest HST Tractors out there

[art]

Be careful with an IH hydro. Nice when they work, but costly to fix. Much more than a gear/clutch tractor.

They can be costly to fix if the shop doesn't know how to. They will give years of service and thousands of hours without issues with proper maintanence.

 

[dfkrug]

There is a lot of inefficiency you are not accounting for.

Actually, the numbers I quoted are from the SurplusCenter hydraulic
calculator, and they do account for the inefficiency of hydraulic drive.
There is no question that direct gear linkage to the engine is more
efficient than using a hydraulic pump and motor, which has a 15%
hp penalty.

 

[SPYDERLK]

god **** you to **** you bastard

Dead member ...

 

[dieselfreak]

Who makes the biggest Hydro out there? I am looking possibly for a hydro that can run my 15' flex wing mower, which requires about 60 pto HP. I would also want an enclosed cab with AC. Does anybody make such an animal?

You can get a full powershift, or the CNH CVT.

Powershuttle/DynaQPS is so easy to use, you would not regret getting it.

df.

 

[radman1]

Actually, the numbers I quoted are from the SurplusCenter hydraulic
calculator, and they do account for the inefficiency of hydraulic drive.
There is no question that direct gear linkage to the engine is more
efficient than using a hydraulic pump and motor, which has a 15%
hp penalty.

I often use the same source for hydraulic needs. If real life it works a little different. My Toolcat has 27+ gpm at 3000 psi to run the rear hydraulic pto. Bobcat rates the pto hp at 25. The calculator estimates about 55-56 hp to run 27 gpm at 3000 psi. I believe that to be realistic. The problem is there is a second motor/pump to run - the rear pto motor. The rear pto motor is no different than if the motor is directly on a tiller, mower, mulcher ect. The motor that drives the attachment also has considerable inefficiency. I think this is what causes the next step in loss of hp. The 25 hp of the TC feels to be correct. However, the next problem is the hp is at max with max flow and gpm. Apply any significant load and the hp now drops to 20, then 15, then 10, then 5 and lastly 0 as the relief valves opens more and more under load. I have used a 6' tiller on a Case-IH dx29 with 29 hp and the same tiller on my TC. The dx29 far outperforms the TC. Both have nearly the same pto hp. Why? The torque and hp of the dx29 will increase as the rpm from pto speed decreases because of the torque curve. One could argue the pto hp of all tractors are underated because of the torque curve. The dx29 can power through the tough spots. The hydraulic TC will fall on its face and stop completely in the same conditions. The diesel engine of the TC hardly notices the difference if the tiller completly stops. The dx29 will stall and die if the tilling conditions are too harsh.

I was involved in evaluating the Bobcat Toolcat pto prototype version. The original prototype had only 20 pto hp and was not high flow. I told them they had to get the pto hp up to handle many cat I 3 pt equipment. Their final version uses hi-flow only in the Toolcat. They initially tried to make the pto direct drive from the engine but it was too complex and costly from an engineering standpoint.