45.6 Cu In Hydraulic Motor
Note that this motor is about 32.5 hp. Note that the motor at Universal_Track_Unit_Conceptual_Design is 30 hp! So bigger is not always so much better. It is surprising that the very small hydraulic motors handle similar power, so it is advantageous to use them, as they have better cost to power ratio. You end up paying for the higher torque, so one solution is geardown. Geardown is not as easy, but if it is more widely replicable, this is a case of Worse is Better
