An experimental engine with an electrohydraulic camless valvetrain, capable of total valve motion control, was built at Ford Research Laboratory. The system uses neither cams, nor springs, which reduces the engine height and weight. Hydraulic force both opens and closes the valves. During the valve acceleration, potential energy of compressed fluid is converted into kinetic energy of the valve. During deceleration, the energy of the valve motion is returned to the fluid. Recuperation of kinetic energy is the key to the low energy consumption.
The system offers a continuously variable and independent control of virtually all parameters of valve motion. This permits optimization of valve events for each operating condition without any compromise.