There’s a reason the industry doesn’t use sleeve valves anymore…

Another “innovation” which is often speculated about is an electronic coil style suspension system to replace the springs and shock absorbers. Bose in one of the recent largish companies which invested a small fortune in that idea. There was a bit of a news splash about their efforts in 2004:

http://www.pcmag.com/article2/0,1759,1640050,00.asp

Infiniti even sold an active suspension option sometime in the 1990s, but it didn’t last in the marketplace.

For some things mechanical/hydraulic systems remain a much better choice than electrical ones …. and I’m an Electrical Engineer.

http://www.usautoparts.net/bmw/technology/valvetronic.htm

It provides 90%+ of the benefits of infinitely variable valve timing while still using mechanical and electro-hydraulic systems.

Also, it turns out that variable valve timing is a high bang-for-buck modification. Much of the benefits come just from being able to vary exhaust cam timing. Ford does this on some engines (Escort?) because the additional benefit of varying intake cam timing doesn’t justify the cost.

They operate at up to 21,000+ rpm, but my understanding is that they are not reliable enough for long-term use in production engines. I’d think Ferrari would have done this in production engines if they could make it work.

As Shaker said, there’s NO WAY to retain seal integrity on rotary valves for the long haul.

I thin we will eventually see solenoid-operated vvalves, as they would give a real boost to emissions and power with infinite variability.

Even going to solenoid-actuated valves won’t work. The idea of infinitely variable timing is so seductive that engineers keep coming back to the idea, but the work required in switching the currents involved is incredible. First, lets get a time scale: an engine running at 3000 RPM means a valve needs to be actuated 1500 times per minute or once every 40ms. Even on a small solenoid like a fuel injector getting 40ms pulse widths is hard and thats only at a few amps of current. It is incredibly hard, if not impossible, to switch the kind of current needed to actuate a valve on those time scales. I know a researcher who needs to switch 2kV at 100A with a time resolution of 50ms and he uses the state of the art electronics that he designs himself and it takes up half of a room. He’s also fixing it every week as the arcs burn through everything.

Lots of work went into that idea and it was found that the energy required to electrically actuate a pure solenoid system is excessive. Valeo has a no cams electro-mechanical system they have been talking about for several years.

http://www.valeo.com/automotive-supplier/Jahia/pid/1317

Don’t hold your breath though, this technology has been any day now for decades.

http://www.roadandtrack.com/article.asp?section_id=36&article_id=5588&page_number=3

I’m not holding my breath, but I wish these innovators the best of luck. Its hard to make something new in the car biz for a plethora of reasons.

If they did away with it I’d buy a Ducati in a heartbeat. As it is, the spectre of expensive valve adjustments every few thousand miles is off-putting.

But I do agree that the next big thing will be direct solenoid activated valves. There are still a number of hurdles to jump with the idea, though. At high rpms the switching speed for a valve needs to be incredibly high, and the technology just isn’t there yet. I have little doubt that it is being worked on, however.

Heh, it only counts when people are actually using it. I think the next “big thing” in valve train technology will be the move to valves controlled by solenoids. Those will be infinitely variable, could act as small throttle plates (a la diesels), and will eliminate much of the mechanical complexity and drag of existing valve trains. Unfortunately, I haven’t heard anything about this tech in a while and it would hardly be the first valve train tech to die a silent death (see desmodromic valves).

http://www.coatesengine.com/wheel_bearing.html

What a joke. Reading that page you would think that worn and improperly adjusted front wheel bearings are an epidemic. I can’t remember that last time I had front wheel bearing adjustment problems on a modern car.

One problem with the Coates valve system is that it doesn’t seem well suited to dynamically adjustable lift and duration like the best modern engines use. I’m doesn’t look like they even incorporated dynamic valve timing.

Their one “customer” appears to be a start up company in Canada which plans to sell natural gas powered generators to the oil and gas industry.

Rotary valve engine designs have been tried for a long, long time. A nice summary history is here:

http://www.dself.dsl.pipex.com/MUSEUM/POWER/RotaryValveIC/RotaryValveIC.htm

The big advantage of a poppet valve is that the engine’s compression and combustion forces act on the valve in a way which just closes it tighter. With a rotary valve those forces are trying to push the rotating assembly away from the sealing surface.

If you want to burn some time, read the latest quarterly report Coates has filed with the SEC:

http://www.sec.gov/Archives/edgar/data/948426/000101376207002188/form10qsb.htm

But I’m okay with vaporware if it isn’t promoted like Tesla’s non-existent roadsters.

Stifling PR is fine, but let’s not do that with creativity.