A valve actuator system is capable of operating a number of valves with a single cam. The system includes a power shaft, a cam mounted around the power shaft and a gear train to drive the cam when the shaft rotates. Hydraulic actuator assemblies corresponding to the number of valves are radially positioned around the shaft axis for operation by the cam. Hydraulic tubes connect each actuator to a valve follower disposed adjacent to the respective valves. The cam profile pressing each actuator plunger in sequence as the cam rotates causes the hydraulic fluid to flow out of the actuator assembly, through the like-numbered pipe, and into the like-numbered follower assembly, which in turn causes the follower plunger to move the like-numbered valve from an open position or a closed position. This occurs sequentially for each valve.