There is enough technology to build a camless engine, and one of the most active efforts in this design approach comes from Freevalve , a subsidiary of Swedish hypercar manufacturer Koenigsegg. The company just released a video that demonstrates the valve action using a electronically controlled pnueumatic valve actuators. In the Koenigsegg engine, each valve is operated by an electronically controlled pneumatic actuator. The idea of a camless engine has been around for years with some success on a demonstration level, and numerous companies are currently pursuing production versions. While the Freevalve approach involves pneumatics, others are working with electrohydraulic and electromagnetic devices that control the valve timing.
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The modern internal combustion engine is a marvel of engineering. The irony here is that camless engines are relatively easy to build. The average hacker could modify a small four-stroke engine for camless operation in their workshop. Suck, Squeeze, Bang, Blow A multi-cylinder gasoline engine is a complex dance. Hundreds of parts must move in synchronicity. Valves open and close, injectors mist fuel, spark plugs fire, and pistons move up and down.
Lobes on the shaft press on tappets which then move the valve stems and the valves themselves. The camshaft itself is driven at half the speed of the crankshaft through timing gears, chains, or a belt. Some valve trains are relatively simple — such as overhead cam engines. Others, such as the cam-in-block design, are more complex, with pushrods, rockers, and other parts required to translate the movement of the cam lobe to movement at the valve.
Exactly when, and how fast a valve opens is determined by the profile of the cam lobe. Everything comes at a cost though. Too aggressive a lobe profile can lead to valve float, where the valves never fully seat at high RPM.
Myriad Solutions Engine manufacturers have spent years working around the limitations of the camshaft. The results are myriad proprietary solutions. Toyota has VVT-i. All these systems provide ways to adjust the valve action to some degree.
VANOS works by allowing the camshaft to slightly rotate a few degrees relative to its normal timing, similar to moving a tooth or two on the timing chain. While these systems do work, they tend to be mechanically complex, and expensive to repair.
The simple solution would be to go with a camless engine. This would mean eliminating the camshaft, timing belt, and most of the associated hardware. Solenoids or hydraulic actuators open and close the valves in an infinitely variable number of ways. There are a few reasons. The advantages of camless engines to camshaft engines are analogous to the advantages of electronic fuel injection EFI vs carburetors.
At the core, a fuel injector is a solenoid controlled valve. The fuel pump provides constant pressure. The engine control unit ECU fires the injectors at just the right time to inject fuel into the cylinders. The computer also leaves the valves open long enough so that the right amount of fuel is injected for the current throttle position. Electronically this is very similar to what would be required for a camless engine.
So what gives? Making a clean, fuel-efficient carbureted engine was possible, but there were so many mechanical and electronic actuators required that the EFI was a better alternative.
All the big manufacturers have experimented with the camless concept. The best effort to date has been from Freevalve, a subsidiary of Koenigsegg. They have a prototype engine running in a Saab. LaunchPoint Technologies have uploaded videos showing some impressive actuator designs LaunchPoint is working with voice coils, the same technology which moves the heads in your hard drive. However, these are giant diesel engines used to drive large ships or generate power.
For the hacker set, the best way to get your hands on a camless engine today is to hack one yourself. Ladies and gentlemen, start hack your engines! Simple, single-cylinder camless engines are relatively easy to build. Start with a four stroke overhead valve engine from a snowblower, scooter, or the like.
Make sure the engine is a non-interference model. This means that it is physically impossible for the valves to crash into the pistons. Add a power source and some solenoids. Examples are all over the internet. The control system is a mechanical wheel with electric contacts, similar to a distributor cap and rotor system.
Note that this project uses two solenoids — one to open and one to close the valve. This route is an excellent stepping stone before making the jump to full electronic control.
Video: See How The Koenigsegg Camless Engine Works
The modern internal combustion engine is a marvel of engineering. The irony here is that camless engines are relatively easy to build. The average hacker could modify a small four-stroke engine for camless operation in their workshop. Suck, Squeeze, Bang, Blow A multi-cylinder gasoline engine is a complex dance. Hundreds of parts must move in synchronicity.
The Camless Engine of the Future Is Almost Ready for the Real World
In these systems, the camshaft rollers and pushrods have been replaced by an electro-hydraulic actuator system which uses the existing fuel pumps, thus reducing development risks of the new system by employing existing technology. This eliminates the risk of mechanical failures that could damage the engine if there was a malfunction while changing directions. Additionally, because there is no chain connection between the crank shaft and the camshaft, the engine is lighter with fewer points of failure. The absence of a camshaft also means that the parasitic load on the engine is lower, which is particularly useful in large marine engines, as it can equate to a large amount of power savings. With a camless engine, fuel injection and exhaust timing are directly controlled by an engine control unit and can be constantly changed and adjusted without stopping the engine.