VARIABLE-VALVE TIMING ALLOWS for controlled scheduling of valve-timing events. When applied to spark-ignition engines, it yields improvements in emissions, economy, and performance. The benefits for diesel engines further include: improved starting, noise reduction, and the ability to vary compression ratios. A camlobe-phasing system which takes advantage of the merits of variable-valve timing has been developed. Some advantages of this advanced valve-timing approach are: 1. continuous control over valve-timing events, 2. independent control over valve opening and closing times, and 3. its application to engines with single-or twin-camshaft arrangements.