If I recall correctly about 6 years ago this was a decently hot topic of possibility regarding the potential future of the Z06... electromagnetically actuated valves meaning no cam necessary and an infinite and instantly adjustable variety of cam profiles.

I don't really understand all of the technologies out there now but I seem to recall some manufacturers (BMW maybe? Maybe even in my own car and I don't know it?? ) coming up with a way to dynamically adjust valve timing on either the intake or exhaust but not both? I dunno... I need a refresher course here. But if I remember it was a very complex and scary system in terms of design, cost, and especially potential repairs.

So have mechanical designs gotten good enough to where electromagnetic designs just don't have as much of a reason to exist anymore or are they still on their way, maybe just taking longer to become viable than had originally been anticipated?

And for that matter what about 36 volt electrical systems? Seems like a few years ago people thought we'd be seeing them by now. Actually maybe cars like the Volt and such will have them... I dunno... but I haven't heard about them on any existing cars. Maybe I just haven't been paying attention. I remember people saying if the electromagnetic valves were going to happen it would require the higher voltage electrical systems, but that they may happen eventually on their own with things like the dynamic suspension systems becoming more power hungry.

 

You can do this by phasing traditional cams on any DOHC motor. It's quite common in today's cars. Indeed, your BMW does it.

You won't see them on street-legal cars until several years after the technology surfaces in racing (e.g. Formula 1), and that hasn't happened yet. I'm not sure what's holding it back, and would be curious to hear what others have to say.

I remember hearing about those too. Didn't they also mention 42 volts as a possibility (maybe that was just the extrapolation based on current 12v systems actually operating at ~14v)? I always thought that those systems sounded promising, but nothing seems to have come of it.

Last I heard, the Volt will have a 300v electrical system and a 12v electrical system.

 

I have no idea how it works but my dad (pilot) was saying something to me about how aircraft engines have been using some sort of camless valve actuation for decades now.

 

I can't find anything online to support such a claim; can you?

Jet engines don't have valves, and therefore don't need cams; I assume that's not what he meant.

 

I don't know about "camless valves"

I do know that piston engine reciprocating aircraft motors have what's called a "magneto" inside.

Basically what this does, is that in the event of a complete electrical failure, the motor will continue to operate by producing it's own spark.

 

Thats a magneto, race cars have them, lots of high performance engines have them.

 

Almost every small engine's spark is produced by a magneto ... think lawnmowers, snowmobiles, motorcycles, etc. A magneto is really nothing more than a small scale alternator, and also produces power to run accessories like headlights. It's a very reliable and compact system, which is why it's used in aircraft engines.

 

This will not happen for a while. There is an engine development spending freeze in Formula 1 for another few years (2011 or 2012?). After it ends, who knows what will happen. Maybe we will see LeMans cars coming out with this technology before F1.

 

The BMW think I think he is referring to is the variable valve lift on certain 6 cylinders from BMW (valvetronic). Really cool when I first heard about it, and still pretty cool. http://www.youtube.com/watch?v=RE5Tx...eature=related

I don't know if things have changed, but when it initially came out, BMW did it on the intake only. Mostly because there is little to gain from varying the lift on the exhaust. While on the intake, you can reduce you pumping losses, eliminate the throttle body, change the amount of air/fuel you take in depending on your driving needs, etc.

As for the 36v and 42v systems, I remember it has something to do with longevity of connections and corrosion build up over a very quick time. Much, much quicker than current 12v systems.

 

the magneto is not a backup system but it is the only system. it works more like a rope start small engine than a car electrical system. it uses rotating magnets to create the spark. no battery is required. in fact, a smaller 4 cylinder aircraft engine could be started by hand-propping with no battery in the aircraft. this will not work on larger high performance radials and V engines(WWII piston engines producing thousands of horsepower). these engines are simply to large and have to much compression to be hand started. aircraft engines also have dual magneto systems. they have 2 separate systems. they have 2 sets of ignition wires, 2 spark plugs per cylinders, and 2 magnetos. this is done so if one system completely fails the engine will continue to operate. i know this because i used to take flight lessons but stopped because it was too expensive. its over 100 bucks per hour with the instructor. i wish i could afford to do it again. i love aviation.

 

The problem holding everything up is how to control the valve on the closing. Just Google electromagnetic valve head and you'll see half a dozen patents on how to create "soft seating" of the valve.

Imagine a camshaft with no closing ramp. Just a straight drop off. The valves or the seat wouldn't last a mile.

 

http://www.sae.org/automag/toptech/02-2001/toptech5.htm

Apparently, Siemens has had the soft seating problem solved for nearly a decade now.

 

I believe that I heard somewhere that the 42V systems ended up having more problems than expected, due to the potential for shorting or arcing at the connectors.

 

I've been very interested in the camless valve operation for almost eight years since I first heard about it. I kind of figured the progression would be gasoline direct injection, electro-magnetic valves, then HCCI. They are skipping the EM vavles. There are some cool advantages to the camless valves such as the variability of the vavle timing/ lift as well as other things. I am sure there are companies still working on it but I haven't seen any movement lately.

 

The disadvantage to systems like Valvetronic is the valvetrain ends up pretty heavy, limiting rev potential (same problem as cylinder shutoff).

It seems to me that DI is a superior answer to both Valvetronic and cylinder shutoff.