Abstract: In a reciprocating piston engine with a variable compression ratio in which a piston is movably disposed in a cylinder, an adjustment arrangement is provided for controlling the compression ratio of the engine including an adjusting part supported by a guide element depending on a signal provided by a detection means comprising a transducer part arranged on the adjusting part and a corresponding detection part, arranged on a housing part of the engine in connection with a control unit in which a desired momentary compression ratio setting is determined on the basis of a characteristic diagram stored in the control unit.