blob,
dvd is assuming your are referencing electric motors. If you are refering to hydraulic motors, you will still have a drag problem (very small) from the idle motor, but you can get hydraulic pump drives from a number of sources (Durst div. of Regal-Beloit, FUNK, EATON...etc.) that will work equally well in reverse (i.e. a hydraulic motor to drive the shaft.
Hope this helps,
FINN