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#16 NUTNDUN OFFLINE  

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Posted April 06, 2011 - 10:32 AM

Not to be argumenitive but with that considered. What makes the Case/Ingersoll Gt's Hydralic Drive so admired and apreciated?


This is just my .02, but I think most of it would have to do with; If you are going to have hydraulic powered implements then with the Case/Ingersoll garden tractors you already have a hydraulic system sufficient enough to support such a thing without having to add another pump to the system. If you wanted to put a angle cylinder on to a push blade it would be as easy as adding a control valve and the cylinder and plumbing it in with the current system.

Where with a gear drive tractor or one with hydrostatic drive you would have to add another pump, unless the hydro is ported(whole other discussion, because the ported pumps wouldn't flow enough for a loader) which would be run off the motor also causing even more parasitic loss. A good example would be my Massey 1655, it has the Sundstrand hydrostatic drive but there is also another pump that is run off of the front pto for the loader.

#17 TUDOR OFFLINE  

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Posted April 06, 2011 - 02:39 PM

You're right. They are just as bullet proof as the top line hydros and have the flexibility to operate additional hydraulic motors without the trials and tribulations of adding an auxilliary hydraulic sustem.

The additional loss from the 2 or 3 gpm charge pump is negligeable, on the order of 0.5 hp, and only when it is used to its max. The charge pump is there to support the hydro first , and since it is already there, making use of it for implement lift is a bonus.

#18 Texas Deere and Horse OFFLINE  

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Posted April 06, 2011 - 02:55 PM

Just thought I would ask a question, or maybe something to consider. In a mechanical or gear driven tractor, by figuring the transmission ratios, don't you actually increase hp to the rear wheels?

#19 olcowhand ONLINE  

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Posted April 06, 2011 - 02:58 PM

Just thought I would ask a question, or maybe something to consider. In a mechanical or gear driven tractor, by figuring the transmission ratios, don't you actually increase hp to the rear wheels?


I don't think so, as HP is tied to the time it takes to do a certain amount, so slowing the wheels increase the time, BUT it does increase the torque...or at least that's how I see it.
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#20 Texas Deere and Horse OFFLINE  

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Posted April 06, 2011 - 03:04 PM

Yes, thats is the right way to say it. You increase torque, not horse power through gear reduction. Thanks for setting my mind straight.

#21 TUDOR OFFLINE  

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Posted April 06, 2011 - 03:10 PM

The main reason for the pump and motor efficiency losses is designed in seepage for lubrication purposes.

A gear pump would not survive if there was zero clearance between the sides of the gears and the housing and between the gear teeth and the housing. Even though they are classed as a positive displacement pump, that leaves a relatively large amount of space for oil to leak by, even with minimal clearances. Vane pumps have similar side clearance seepage, but the vanes are much closer to the housing (molecular clearance). Piston pumps cut the side clearance issue in half with only one valve plate, and individual piston clearance which can be better controlled in manufacture and use. The pistons don't have to deal with the wear of shaft bearings like the gear and vane pumps do.

The clearances also have to deal with a wide ambient temperature range for the parts of the unit, plus shaft bearing wear/wobble in the gear and vane pumps. A couple of thousandths of an inch clearance at 2000 psi is a very noticeable amount of seepage.

#22 DH1 ONLINE  

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Posted April 06, 2011 - 04:59 PM

Efficiency ratings of hydraulic pumps and motors.

Piston - 90%
Vane - 85%
Gear - 75 -80%

For a pump/ motor combination

- Piston to Piston (.9 x .9) - 81%
- Vane to Vane (.85 x .85) - 72%
- Gear to Gear (.8 x .8 best case) -64%
- Gear to Gear (.75 x .75 worst case) - 56%
- Piston to Gear (.9 x .8 MF12H) - 72% or 68% using the lower number , but Sundstrand has pretty good equipment.

Wear can change things , but these are the theoretical numbers used for basic design of a system.


Thanks Bob, when I first started this thread I had a few members in mind that I hoped would respond and you were one of them.
This is the kind of info I was really looking for and your #s match more or less what has been said earlier.
My MF12Hydra has a 12hp engine and if you apply these #s you have 8 to 9 usable hp for the wheels max.
The benefits to me of Hydros still out weigh the losses, it's just the nature of the beast.
This weekend I'm going to try to do a Video on Hydro vs gear drive tractors under heavy loads, I have a 67MF12H and a 66MF10 gear drive, will see how they compare pulling stuff, and I'll show you what I mean about loading down my Hydro almost to the point of stalling it out.

Anybody have any comments on this issue I would like to hear them, the more info the better.
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#23 NUTNDUN OFFLINE  

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Posted April 06, 2011 - 05:22 PM

Thanks Bob, when I first started this thread I had a few members in mind that I hoped would respond and you were one of them.
This is the kind of info I was really looking for and your #s match more or less what has been said earlier.
My MF12Hydra has a 12hp engine and if you apply these #s you have 8 to 9 usable hp for the wheels max.
The benefits to me of Hydros still out weigh the losses, it's just the nature of the beast.
This weekend I'm going to try to do a Video on Hydro vs gear drive tractors under heavy loads, I have a 67MF12H and a 66MF10 gear drive, will see how they compare pulling stuff, and I'll show you what I mean about loading down my Hydro almost to the point of stalling it out.

Anybody have any comments on this issue I would like to hear them, the more info the better.


Doug, I think a real world comparison is an awesome idea. Especially when it is the same model tractor and gear vs. hydro. Would just have to come up with a measurable test that could be documented.

#24 DH1 ONLINE  

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Posted April 06, 2011 - 05:28 PM

Doug, I think a real world comparison is an awesome idea. Especially when it is the same model tractor and gear vs. hydro. Would just have to come up with a measurable test that could be documented.


Well I got to find something that the Massey's can barely move and that I can move around back to a staring point.
I have 1 set of loaded turf tires and cast wheel weights that can go on both tractors plus add some extra weight under the seat of the gear drive just to try to make everything the same.

#25 TUDOR OFFLINE  

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Posted April 06, 2011 - 06:22 PM

Well I got to find something that the Massey's can barely move and that I can move around back to a staring point.
I have 1 set of loaded turf tires and cast wheel weights that can go on both tractors plus add some extra weight under the seat of the gear drive just to try to make everything the same.


Don't bother trying a travel trailer. My old MF12H had no problem pulling our 18', 3600 lb trailer on the driveway at any speed or power setting you'd care to use.

Pulling a load uphill will load the hydro pretty good.

#26 JD DANNELS OFFLINE  

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Posted April 06, 2011 - 08:51 PM

Thanks for answering my question! I was in no way attacking the Case/Ingersoll GT's in fact I would like to have one.
When I was a teenager in the mid 60's my Dad bought a 310 Case with loader and Shuttle shift.
Of all the tractors I have driven over the years that's my favorite.
If I could find one of those 600 series Loader GT(exact model # escapes me) I'd jump on it in a New York Minute.

#27 broken2 OFFLINE  

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Posted April 06, 2011 - 09:38 PM

Well I got to find something that the Massey's can barely move and that I can move around back to a staring point.
I have 1 set of loaded turf tires and cast wheel weights that can go on both tractors plus add some extra weight under the seat of the gear drive just to try to make everything the same.


I can't wait for the comparison. Be careful, I've had my mf12g standing tall on the rears more than once.

#28 TUDOR OFFLINE  

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Posted April 07, 2011 - 12:17 AM

My MF12Hydra has a 12hp engine and if you apply these #s you have 8 to 9 usable hp for the wheels max.
The benefits to me of Hydros still out weigh the losses, it's just the nature of the beast.
This weekend I'm going to try to do a Video on Hydro vs gear drive tractors under heavy loads, I have a 67MF12H and a 66MF10 gear drive, will see how they compare pulling stuff, and I'll show you what I mean about loading down my Hydro almost to the point of stalling it out.

Anybody have any comments on this issue I would like to hear them, the more info the better.


Doug, a caution here. I don't know the specs for the MF12H transmission, but I would guess that it is probably about a 7 hp unit just from the physical size. That gives a 5 hp output, more than enough to spin the wheels in dirt with the axle loaded to the max rating of 750 lb static load.

If anyone has one of these hydros in non-functioning form and disassemled, I would appreciate knowing the diameter of a piston, the number of pistons, and the diameter of the piston bore circle. In thousandths of an inch please. This country may have gone metric, but I haven't. PM the info to me please. Thanks.




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