Abstract: An improved electro-hydraulic intake and exhaust valve actuator for a “camless” internal combustion reciprocating engine. The present invention integrates an electric motor driven “plug type” rotary control valve and a single acting hydraulic cylinder in one housing for the actuation of an engine valve. The geometry of the hydraulic ports in the rotary control valve may be tailored for desired valve actuation profiles. The electronic control of the rate of rotation and angular position of the rotary control valve are used to infinitely vary the engine valve operating parameters. Thus, engine valve timing, speed, cycle duration and lift may be varied. A rotary control valve permits high speed operation and accommodates a broad range of valve sizes. Availability of a wide range of commercial open frame brushless electric motors and dedicated integrated circuit controllers contribute to the cost effectiveness of the present design.