A reciprocating machine includes a cyclical kinematic chain in which power is transferred between translational and rotational motion. The kinematic chain includes a piston (2) reciprocating in a cylinder (1), connected by two connecting rods (9, 10) to dual counter rotating crankshafts (7, 8). The crankshafts (7, 8) are displaced symmetrically from the axis of movement of the piston (2), and the crank pins (15, 16) of the crankshafts (7, 8) to which the connecting rods (9, 10) are connected are symmetrically aligned about the axis of movement of the piston (2). The connecting rod small ends (13, 14) abut at their connection to the piston (2). The distance between the axis of the dual crankshafts, the length of the connecting rods, the positioning of the connecting rods connections to the piston, and the diameter of rotation of the crank pins about the crankshaft axes are such that in motion the ratio of the length of each stroke of the piston to the diameter of rotation of the crank pins about the crankshaft axes is at least 1.1 to 1.