The Camless Engine

A few years ago, Koenigsegg, the Swedish manufacturer of hyper-cars showed off a new style internal combustion engine: the camless engine. Specifically, it was a subsidiary called Freevalve that showed the engine.

The idea is relatively simple – which is often the basis for many great ideas! If you remove the cams that open and shut the valves, you can not only lighten the motor by ditching the camshafts but also the chains or belts that drive the timing of the motor. Importantly, you free up a bit more power that is lost trying to keep everything in sync. In this respect it is like replacing the engine-driven cooling fan with an electric one – less power is wasted in keeping the whole unit running.

Freevalve have replaced all the equipment mounted on the cylinder head with electro-hydraulic-pneumatic actuators that move the valves. So rather than the valves opening and shutting in time with the piston’s position, they can be electronically opened and shut. In a traditional engine the cam lobe defines how long the valve is open and on a variable valve engine, such as the F20C from Honda (which I have had experience with), a secondary cam lobe is used to provide a more aggressive profile for better performance.

With the traditional engine, the valves can only be opened thanks to a specific cam lobe shape, so apart from the speed of the engine, the motor will always use the same level of tune. With electronic opening of the valves, this can be changed by mapping the actuators for specific purposes which in theory could give a huge range of options depending on the usage of the engine.

The engine can be managed much more efficiently by understanding the load being placed on it and therefore it could be combined with several other technologies to provide a highly efficient motor with very low emissions for road use and yet could be a beast on the track.

As described above, the removal of a substantial part of a traditional engine means a significant weight and size reduction which then means that the engine can be placed into a different part of the car – not necessarily in the traditional places. Freevalve quote an engine design that was 20kg lighter than the motor it was based on and smaller by 5 to 7 centimetres in height and width.

Freevalve are still developing the technology and it will be interesting to see if they start licensing it to other mainstream manufacturers to bring in a revenue flow.