A ball-lift device with screw for a variable compression ratio engine having a hydraulic double-acting control actuator (8) including an upper chamber (121) and a lower chamber (122) and at least one actuator piston (13) connected to a control rack (7) includes: at least two balls (401, 402) or valve elements each resting on a seat (403, 404) and closing off respectively one and the other end of a transfer channel (405) connecting the upper chamber and the lower chamber of the control actuator, the balls acting as a nonreturn valve element when they are held on their seat by a spring (408, 409) in order to allow the hydraulic fluid to pass in only one direction; and lifting element (410) including at least one electric motor (480) designed to rotate at least one screw (481, 482) making it possible to lift from or place on its seat at least one ball.