Automotive designers have been working on the idea of engines without camshafts for many years. Camshafts add complexity, weight and friction to engines. Due to it's physical profile, a cam can only control the movement of a valve within limited parameters, that won't be optimal for all operating conditions. Advancements in variable valve timing technology, in recent years have improved performance and efficiency. However, these VVT systems add still more mechanical complexity and weight.
The holy grail is to eliminate the camshaft all together and control every valve independently. French supplier Valeo now has several development contracts with car-makers to test their electro-magnetic valve control. Engines with electro-magnetically solenoid control of the valves would have less friction and the timing could be optimal under all conditions. Lubrication of the top end of the engine would also be simplified. According to Valeo the valve actuators are no longer a technical barrier but sensors are. The need for accurate input signals is critical to make the system work as is the need to ensure that the sensors last the lifetime of the engine under extremely difficult operating conditions.
Currently the camless engines are still more expensive than conventional engines. A four-cylinder engine with electronic actuation on only the intake valves is expected to cost about €300 more to build (still less than the premium for a diesel engine, though). This half-camless engine could achieve a 15 to 20 percent improvement in fuel economy, without any sensitivity to fuel quality, unlike direct injection systems. Valeo expects to see a camless engine on the market by 2010 or 2011. More details on Valeo's smart valve actuation are available at their site.
[Souce: Automotive News - subscription required]