A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively, to which the camshaft is inserted and of which relative phase angles with respect to the camshaft are variable; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing in which the first and second inner brackets are rotatably inserted, and on which a control slot is formed; a cam cap rotatably supporting the first and the second cam portions and to which the slider housing is slidably mounted; a control shaft which is parallel to the camshaft and on which a control rod is eccentrically formed; an eccentric plate rotatably connected to the control rod and rotatably inserted into the control slot; and a control portion selectively rotating the control shaft.

A variable combustion system for an internal combustion engine, which suppresses mechanical compression ratio change control by a variable mechanical compression ratio control mechanism and carries out internal EGR amount change control by a variable valve actuating control mechanism on a preferential basis in a first operating region in which a compression self-ignition combustion is carried out, and which suppresses the internal EGR amount change control by the variable valve actuating control mechanism and carries out the mechanical compression ratio change control by the variable mechanical compression ratio control mechanism on a preferential basis in a second operating region in which a spark ignition combustion is carried out.

A control method and apparatus for a variable engine valve operating control mechanisms which move the engine valves to a safe lift/timing position with respect to a piston to minimize the potential for valve to piston contact during valve surge. At least one engine operating conditions is selected and provided with a threshold triggering a control to move the valves to a safe position in a calibrated, predictive manner in advance of any potential valve to piston contact. The control method and apparatus can be integrated into the existing engine control and variable valve operating control mechanism.

A variable valve device for an internal combustion engine is equipped with a variable valve mechanism capable of changing the working angle of an intake valve while holding the maximum lift amount of the intake valve constant. The variable valve device retards the timing for closing the intake valve as the load of the internal combustion engine rises, and enlarges the working angle, while holding the timing for opening the intake valve constant. Operating characteristics of the intake valve are provided in accordance with the load of the internal combustion engine.