Couple of comments:
I don't think 14 gpm is optimal for blowing snow with a hydraulic motor.
I's agree - it probably isn't
optimal - but it must be
at least workable (see below)
I would guess it would depend on several things:
1. Size of the blower
2. Size of the hydraulic motor
3. Type of transmission (HST being more ideal in terms of controlling ground speed)
4. And probably most important: System pressure (since pressure is what develops force/torque)
Allied/Buhler does make hydraulically-driven snowblowers for commercial use - at the low end, their specs list 13 gpm (@ 2000 psi) as the minimum for a 60" blower:
Farm King Commercial Blower Specs
In the above application they use a motor with a displacement of 6.2 cu in (for units that flow 13 to 17 gpm) - and, in fact, they list the "Eaton Part No." of the motor as being 104-1062
Larger flows get a larger displacement motor - covered at the bottom of page 19 of the manual located here:
Operator and Parts Manual
I run 27 gpm on my Toolcat and sometimes that is marginal in really deep snow with 66" blower.
Dunno .... maybe an issue with correct sizing of various components in the system (too little displacement on the motor maybe ?) ... or it just may be the nature of the beast ?
If you go with a motor that has more torque, you will loose rpm and that could be an issue with chute plugging or not throwing snow far enough.
True, I would think.
Allied/Buhler handles the plugging issue by restricting flow to the auger, diverting more to the fan - once the fan clears flow is restored to the auger.
From page 13 of the above manual:
"Hydraulic Control Block
Non-stalling fan feature:
The hydraulic snowblower has a unique modulating element that keeps the blower fan from stalling in an overloaded condition. This is accomplished by starving the hydraulic flow to the front auger motor (which then stops feeding the fan) and diverts all of the flow (and energy) to the main fan motor. As the fan clears itself, and the pressure drops, the auger again begins feeding according to load. When the system is set up properly the fan motor should not stall or plug up."