Andrey:

In order to begin operation, electromagnetic valvetrain should oscillate valves with increasing amplitude in order to reach lockable open/closed position. I am kind of puzzled how such mode of operation allows for start/stop engine operation and cylinder deactivation.

Raphael:

Such systems exhibit high electric power demand, in part because unlike cam-based drives they do not recuperate energy as the valves close again.

The valves do recuperate energy, but it's mechanical recuperation, not electrical. Each valve is driven by a spring with a high force constant, whose neutral position is midway between open and closed. The resonant frequency for the valve + spring is somewhat greater than the maximum frequency at which the valve must operate at engine redline. When the valve opens or closes, it is not driven by electromotive forces. Rather, it's driven by the force of the spring, when the electromagnet that holds it open or closed against the force of the spring is switched off. It accelerates rapidly toward the neutral point, passes through that point, and then decelerates rapidly toward its other extremum. As it approaches the other extremum, the electromagnet at that end of its travel draws it with enough force to compensate for frictional losses, and then holds it. It continues holding until it is switched off and the next transition is initiated.

Think of it in terms of a child on a swing, with one parent on either end of the swing arc. The parents don't push the swing, they draw it toward them and hold it for a time. When they release it, it swings over to the other parent.

When the engine has been sitting with no power to its electrical system, the valves are settled at their neutral rest position. Before starting the engine, it's necessary to pump them until their natural oscillation reaches the point that the electromagnets can grab an hold them. But that only takes a few hundredths of a second.

Thanks, Silverthorn, for so clearly elucidating the mechanism of this electrical valve. Very Neat!

I suppose that the valve can be kept open or closed for extended amount of time at will by the force of the elctromagnets. When the valves are held in the closed position, engine free-wheeling will be without pumping loss, easily allowing for cylinder deactivation. Smart, very smart!

But still, quite a large current will still be needed initially for the valve activation phase for a high-performance high-rpm engine that requires quite a hefty spring. Once the valve is in motion, the magnetic force can be reduced somewhat, but still quite large at low engine rpm when the valve must be held closed or open for relatively long period of time against a strong spring force. Electrical loss due to resistance in the winding can still be quite high. This electrical loss is not recuperable.

Continue with my previous posting:
Now then, instead of using stiff springs to recoup reciprocating energy, regenerative braking from the electric magnet is used, then electric current needs not be high at low engine rpm, only at high engine rpm. A circuitry involving a fast-acting power semi-conductor and a large capacitor to store recuperated electrical energy will be needed. Both magnets will be used to push and pull the valve to opposite direction respectively, and then, once the valve is accelerated, regenerative braking will be applied to bring about a soft landing of the valve while the capacitor will store the regenerated energy. Then, the capacitor will dump this energy with a little extra energy to overcome friction and resistance, and, bingo, very weak springs will be needed, and at engine speed at high-way cruise, very little electrical loss will incur.

It would help a lot if there were direct comparisons of cylinder deactivation via regular and whoop de docam system. Unfortunately, this technology is probably moot,
at least if electrics and plug-ins make the progress
I'm anticipating they will.

kerry,
The recent advancements in battery are quite breathtaking. However, due to limitation in mass availability of key battery materials (eg. lithium, cobalt, nickel, lanthanum, etc...) AND long charging time in hours for BEV vs. minutes for fuel fillup, don't expect BEV to replace ICE in any significant quantity anytime soon. ICE-vehicle and ICE-HEV will be around for a very long time to come!!!

I would agree Roger. I think hybrid FFVs will become popular, we will see E5 and E10...and perhaps the CNG car will find a niche as well.

E5 and E10 don't increase overall efficiency.  The best way to use ethanol with gasoline is as an octane enhancer under turbo boost, like the Ford/MIT engine.  They claim a potential 30% improvement due to greater turbo-boosting and engine downsizing.  To do this, the ethanol must be supplied as a separate fuel; it could also be used instead of gasoline if it was available in greater quantities, which won't be for a while.

CNG cars are going to run up against declining NG production in N. America.  This has no future.

The only real option is the PHEV.

PHEV is no doubt a very promising option, but by no means "the only real option." Bio-methane and hydrogen from renewable energy sources are other equally real options, and are carbon-neutral.

Since a very small percentage of electricity in the USA is produced from renewable energy such as wind and solar, a PHEV is, for now, also largely dependent on fossil fuels such as coal and natural gas with some nuclear mixed in. Natural gas and hydrogen can also be made from coal with source-to-wheel efficiency just as good or even better than a PHEV or BEV.