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Valeo In Development Contracts for Camless Engine; Projections of Up To 20% Improvement in Fuel Efficiency

Valeo’s camless Smart Valve Actuation technology. Click to enlarge.

AutoWeek reports that Valeo SA has several development contracts with automakers for its camless engine. Although Valeo would not confirm the contracts, a spokesperson said the supplier is working with several global automakers on camless engines.

Camless technology is projected to deliver as much as 20% better fuel economy over a conventional engine.

Valeo presented its camless Smart Valve Actuation (SVA) at the 2005 Frankfurt Motor Show. In a camless engine, each engine valve is operated individually by an actuator that is placed on the upper surface of the cylinder head, directly above the valve guides. Each actuator is linked to an engine-mounted Valve Control Unit (VCU) that ensures the optimal positioning of all valves and performs the power drive function.

The SVA system thus replaces the conventional mechanical cam belt, camshaft and hydraulic cam followers.

By controlling residual gases, minimizing pumping losses and deactivating cylinders and valves, this technology reduces fuel consumption and pollutant emissions by up to 20%. Consumers will also benefit from enhanced performance and driving comfort, due to an increase in low-end engine torque.

Valeo is working on two different camless systems, each one including the actuators, the Valve Control Unit (VCU), the wiring rail and the Electronic Control Unit (ECU) with the specific strategies dedicated to these new concepts.

The “full-camless” system manages the valves on both the intake and exhaust side of the engine. The “half-camless” system manages the inlet valves only.

Martin Haub, Valeo board member for R&D, told Automotive News Europe that Valeo is focusing on the half-camless system, which delivers 80% of the performance of the full-camless system, but at half the cost.

(A hat-tip to Patrick!)



They are projecting that the "half cam" version can be mass-produced for around $400 more than the standard cost for a gasoline engine.


This might give start from stop systems a run for their money. Similarly for GM version of the 2mode hybrid. On the flipside, 2mode offerings from BMW or Mercedes Benz may offer both the camless valves, and hybrid powertrain. Combined with DI, and a few other features, they may be able to offer 4-5 sec 0-60mph, with 30-35mpg, in a C or D size car.

Lou Grinzo

Am I the only one who read this article and practically yelled out loud, "Where the hell was this idea 20 years ago???"

I know--getting even a "simple" idea like this to work properly under all conditions is likely quite a challenge. Regardless of the details, this technology could be retrofitted onto existing engine designs with enormous benefit.


20 years ago, reliable microcontrollers with the processing capability (I imagine the sensors with finite enough "sensing" relies on 32bit DSP), accurate digital sensors, and low cost electronics did not exist. I may be mistaken but I believe it still requires a 42V electrical system (which is much easier to convince an auto maker to deal with today given the prevalence of micro, mini, and full hybrids and the pressures around the world for greater fuel economy).

Roger Pham

Good idea! Wondering, though, what would be the electrical demand from the entire system? Would the gain in fuel saving offset the greatly increase in electrical demand from all these huge electro-magnets that can generate over 100 lbs of force?

In a conventional cam-actuated valve train, the work done required to overcome the valve spring to open the valve will be returned back to the camshaft when the spring forces the valve to close, thus the spring act as an energy storage device. Friction in the valve train is the only source of power loss.

Is there provision here to capture the EMF generated when the armature is returned back to the closed position from the energy stored in the spring, hence reducing the electrical demand on the system? If so, then the resistive loss in the electromagnet winding may be no more than friction in the valve train of a cam-actuated valve system.


I know of one customer. Mercedes-Benz AG. They are using it in their 2 liter I4 KDI (kmopressor direct injection) debuting on the C-class. Can't wait to see what the fuel economy will be.

The really big boon, other than fuel economy, will be the ability to tune the power curve. The ability to do basically whatever you want to with valve positions gives one the ability to have a very flat torque curve. I wouldn't be surprised if BMW and Porsche are the next ones to pick up this technology.

As time goes on and production is ramped, I'd imagine that this technology will be less expensive than traditional cams. Why? Not as much time tuning/engineering cams to survive vibrations and achieve a specific power curve.


Patrick, the 100lbf is required to keep the cam in contact with the roller or rocker arm contact, when the cam goes away most of the forces go with it. The compressive force from the piston serves to seal the valve.

Hotrod Magazine did an article about an experimental magnetic valve actuated Ford Pinto Engine; this was 20 years ago but it only ran on a dyno under controlled conditions.

Bob Bastard

Can't see many downsides to this other than cost, but that should come down over time, especially if/when it catches on, and you have economy of scale. On the positive side, you have enhanced performance, fuel economy, and likely better engine longevity. Plus, no need to worry about bent valves from a broken timing belt/chain.

Roger Pham

The >100lb-force is required of the spring to keep the valve from floating at high rpm due to the inertia of the valve that increases rapidly with increase in engine rpm.
Smaller DOHC valves have a lot less mass, hence less inertia that would allow higher engine rpm or weaker valve springs, but high-rpm engine will always need strong valve springs.
The situation is not different here because the mass of the valve itself would still be there. Now, we also have to worry about the additional reciprocating mass of the "armature and vane" in additional to the mass of the valve itself! I hope that they can make the armature and vane real light, thereby keeping the electrical current required for valve actuation within reasonable limit!

Roger Pham

Well, on a second thought, having electro-magnets on both ends can greatly reduce the force required from the springs. Force required to move the valve increases as the square of the engine rpm, and at typical cruise speed at~2000 engine rpm, relatively little force will be required. At higher engine rpm, the alternator can put out higher currents in order to power the electro-mechanical valves.


I dreamed of this 30+ years ago when I was working on a 4 bit microprocessor design. I thought, "why don't people do this?"

hampden wireless

In the past the power required to do camless like this would have been hard to do in a regular car electrical system. The power controllers were not efficient enough nearly doubling the power consumption. Now with hybrid and other power technologies this is within reach. This technology can allow the engine to switch from Otto to Atkinson cycle electronically and turn off any # of cylinders. Its gonna cost more then $400 for a half version for a long time though.

Robert Schwartz

Potential long-term impacts of changes in US vehicle fuel
efficiency standards by Roger H. Bezdek and Robert M. Wendling in 33 Energy Policy 407–419 (2005)

Estimates that camless valve actuation technology should produce an efficiency gain of 5%–10% at a cost of $280–$560 per engine.

Up to 20% seems to be a bit of a stretch


Do you think it would be a good idea to use elecromagnetic rotary valves instead of poppet valves? That way you could adjust the valve timing over a wider range and a malfunction wouldn't ruin the engine. Also, there would be less distortion of the intake and exhaust air flow. I know this would mean more R and R costs; however, the improved air flow would most assuredly make the engine more efficient.


I've been reading about this general concept for close to 30 years; the technology to implement it wasn't there until recently. It will be one of the single biggest steps in the on-going development of the IC engine. I take the 20% efficiency gain with a grain of salt, but even a solid 10-15% would be great. The other aspect of this is that it is the final step in decoupling all accessory drives from the engine. Recent developments in electrically driven water pumps, AC, power steering, (all developed for hybrids) means that the impetus to go mild hybrid across the board is very great. With the 42 volt electrics and batteries necessary for both the electric motor as well as all the accessories, and you have a blueprint for the future non-full hybrid standard car, one that could achieve 20% to 30% gains over the current conventional equivalent car.

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