Welcome to the next step in engine technology. Camless engines use solenoid valves instead of the conventional camshaft, cams, gears, rocker arms combination. Solenoid valves are driven electronically allowing completely freedom of valve control. A computer controls the opening and closing of the valves instead of cam lobes actuating rocker arms. The abscence of all that mechanical bulk allows for a lighter and more compact valvetrain package. It also means you don’t need a timing belt anymore.
Camless engines have been around for the past 5 years in testing phases and used in competitions but I do not know of any that have been put into production cars yet.
It’s the next logical step from the current variable valve timing and cam profile phasing technologies that try to go around the limitation of a camshaft’s fixed timing properties. With the flexibility of the valve being electronically controlled, you can have maximum torque at all engine revs and the best fuel mileage possible. A racing cam is shaped to optimize engine output at high speeds without regard for the way it roughens up an idle. With camless valvetrains, we don’t have to live with that.
There is a very good explaination on camless engines pros and cons in this issue of Mechanical Engineering Magazine.
Why am I talking about camless engines of all the sudden? Because we could to see it in road cars soon. The 2007 W204 Mercedes Benz C-Class is expected to be the first car from German marque to use a camless engine.
Mercedes calls it the technology KDI EVT. The KDI EVT is supercharged, with direct injection and uses an electronically controlled cam-less valvetrain. KDI EVT is likely to stand for “Kompressor Direct Injection Electronic Valve Train”. Just a wild guess. :P
I believe this could be the first implementation of camless valves in a production car, assuming no one beats them to the 2007 release date.
There are no details on exactly how the engine works, and what exactly is being used to actuate the solenoid valves, but if I get any information I will write about it rightaway. This will definitely be interesting.
Further reading:
Siemens Automotive Camless Engine
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Lotus been developing this since 2003. Dunno why they are slow to release it.
Lotus AVT camless
That's amusing. While parent company Proton has yet to come up with a variable valve timing solution for it's Campro engine, subsidiary Lotus already has cam-less engines.
hoish.. more new technology.. and i still dun understand how the i-vtec operates.. supposedly to be a combination of camshaft and valve manipulation so that the engine can give what a vtec engine can give? higher output at lower rpms? izzat rite? heh.
why dose the return spring have to excist
So that if there is a failure of the solenoid the valve automatically closes and doesn’t contact the piston crown.
the problem is…it does not work-or have a bit prob.- on high rev…seriously…livin out the mechanic part have a lot to consider….eventhou its lighter,more efficient,without belt whatsoever…the elect part will have to tolerate with the temperatur…if its gettin hot…then some laggin will accur..thats actually the problem with bmw f1 car last seasson..the try to put camless and substitude it with hydraulik valve…and walla…problem when at high revs,..pressure from kompressure hydraulik drop, which then laggin the valve opening..i remember my old prof said b4:…in mechanical/automotiv tech..lotsa things being brought in and most of them involve electronik…but actually the forget 1 thing,….the thing that bring us from point A to point B is not the electronik parts, but actually the mechanical part….!
Don’t compare hydraulic to solenoid. We already know how to get from point A to point B now lets do this better, this is called progress and without progress we wouldnt have our pistons valves and stuff . . .
Actually Lotus has been developing the AVT (Active Valve Train) since before Proton took over. And currently the AVT is already available. If I'm not mistaken, the main purpose of having a completely 'active' valve train is not for performance purposes, but for environmental purposes. AVT is seen as the answer to CAI technology (Control Auto Ignition) to increase fuel economy and reduce emissions. In lament terms, this means that the fuel and air mixture is combusted without the use of a spark, thus combustion is more controlled, and peak temperature is low so it reduces NOx emissions. Pre-AVT, the problem with CAI was that it only can be used in a really narrow band of rpms, and also it needs a substancial amount of exhaust gas recirculated back into the cylinders (EGR). So what was needed to apply CAI technology is a method to 'convert' a normal engine with spark ignition to an engine that supports CAI and back again, depending on the requirements of the user and also the engine running conditions, via actively changing the valve timings. AVT is the answer to this problem, and I'm pretty sure, extensive research is currently being done on this subject. Don't get me wrong, performance wise, having a camless v/t is deffinitely desireable. But this is already achievable with cam phasing and vvt. As far as Proton are concerned, I expect a cam profile switching version of the Campro to be out sooner rather than later.
fuiyyo… more and more high tech, wonder when we all can afford a flying car… just like the Delorean in the back to the future…
Jawa,
Speaking of flying car, there is one company who had designed and built an example of such machine named The Skycar. Very interesting, and you can refer to www.moller.com to see how it looks like.
Camless valve technology will reinvent the wheel. Besides the obvious gains of weight reduction and internal engine friction, it will give a whole new meaning to "sleeper". You can have an engine that will idle as smooth as an exotic V-12 but at high rpm, you can have the broad cam profile of an NHRA Top-Fuel dragster. So at the light it's acting like grandma's Buick Century, but when you hit the loud pedal, large plumes of smoke emit from the tires, and before you turn your head around to see the other drive wayyyyyyyy behind you, you'll already need to be grabbing second gear. And, we can program the software to automaticaly give maximum valve lift and duration at WOT, so banging into second gear will give more than a chirp from the hides. Starting will be so much easier, engine life will be significantly longer and it will rev a lot smoother and a lot quicker. Not to mention the consumption loss. Coming from someone who recently was driving across a dark interstate in Ohio (USA), and the timing chain just….broke. Yeah, camless valve technology IS the wave of the future.
Ducati has developed their mechanical valvetrain system which eliminates valve springs… well, sort of. There is a spring, but not around the valve stem. It does have its possible serious side effects, as explained here:
http://en.wikipedia.org/wiki/Desmodromic
I think last time MAzda has come out with camless engine?
I think you might find that this system will eventually weigh more as the solenoid or electromagnet(s) will end up compensating for the lose of the camshaft and belt I am doing a university project on this using electromagnets but trying to get away from springs as control methods for cam shape looking gd anybody think they have some decent reservh material on this? that would be great thanks all.
i m working as a project on camless engine by d using of solenoid valve bt dere r some pbm in case of solenoid vave it get demagnetized above 1600 degree Celsius………so how can i remove this pbm plz suggest
At 1600 C you shouldn’t have any molecular structure left to facilitate an organized magnetic field. Literally, at 1600 C you have bigger fish to fry.
if you have sufficient cooling then the engine should not reach 1600 degrees celsius there not loosing magnetisation.
The main problem is that progressive and gradual oppening of the valve is important for internal combustion engine's equilibrium. That's why the shaping of the lobes are so critical in a camshaft design.
A supercharger, however, could make easier for the engine to achieve optim equilibrium, since engine engine breathing is presurized and in those conditions progressiveness in valve oppening is less critical.