Abstract: A hydraulic power unit combining a number of cylinders using ball bearings to displace hydraulic fluid sequentially with controlled flow to a number of hydraulic actuators. A power unit could combine a minimum of two cylinders through ten or twelve cylinders in a practical hydraulic power unit. The inherent bi-directional nature of this combination of fluid displacing ball bearings, cylinder and porting arrangement offers a unique opportunity to change fluid flow by reversing input drive. The torsional reaction component of the opposed reciprocator drives is utilized to rotate the core cylinder assembly to realign outlet and return fluid flow. This realignment can be used to reverse the fluid circuits or redirect the fluid to other work.