Abstract: This invention relates to a mechanism and a process by which hydraulic pressure principles may be applied to any reciprocating or rotational means, for instance a piston or a motor, to make the energy output thereof more efficient per unit of energy input into these machines. The unitary hydraulic unit comprises a first larger reservoir cylinder and a second smaller reservoir cylinder which is fluidly connected to the first larger cylinder. Energy is input onto the force receiving surface of the first larger reservoir cylinder and force is hydraulically transferred from the first larger hydraulic cylinder to the force transferring surface of the second smaller hydraulic reservoir. In a preferred embodiment, this two-reservoir system can be applied to any machine with a rotational output by means of a disclosed power conversion means. An efficient power takeoff means for converting reciprocal energy into rotational energy for use in connection wiht the unitary hydraulic unit is also disclosed.