yoyoguy2

i think the key is all these other ideas (electronic, hydraulic, whatever) use MORE parts, when the issue is with speed. in reality, cams, especially with solid lifters, are fairly directly connected to the valve. all this other stuff seems like it would add in more delay between the open signal being sent and the valve getting open. that's the idea of the rotary valve, only one part. i can see that the seals would be an issue though, as the constant scraping of the valve along the seal edge would wear it down. rotary engines do it though, on the apex seals, as do other engine parts like crank and rod bearings, so it seems like it should be possible.

KuHL 951

There have been patented rotary valve designs going back to the 20's. Coates has held the patent on his version of the rotary valve since 1990. I agree with Randy, the real world bugaboos of this system must exist or an automaker would have picked it up by now. The future of electro-hydraulic valves is probably the next wave. I may be wrong but didn't the Acura NSX experiment with an electro solenoid system back in their early racing development but settled on the VTEC due to heat problems?

Geo

Yep. I used to work in the parts biz and read the industry trade magazines. This has been in the works for quite some time. We are simply reaching the capacity of the 12v systems. It's going to happen. It's just a question of when. I've heard rumors of BMW introducing a 48v system.

Laust Pedersen

BMW bought the rights to an electromagnetic valve actuation system from Aura Systems in El Segundo late 1990’s, but I believe that the actuators ended up being too large and the power consumption was taxing the alternator too much.
As you may know they (BMW) now have mechanically actuated, fully controllable valves (open, close and lift) in their latest engines eliminating some pumping loss, by also serving the function of the traditional throttle body. I believe the 745Li was the first to arrive here with this technology.

The main challenge in designing electro-magnetic and electro-hydraulic valves is in creating soft seating under all conditions (engine vibration, overcoming combustion pressures at exhaust time, etc.).

Laust

Geo

Electronically controlled valves will do away with cams and will allow total dynamic control of lift and duration for incredible power once the solenoids can be made to operate quickly enough and reliably enough.

Danno

Yeah, I think valvetrain technology is evolving towards that. Lots of this kind of stuff have been tried in F1 racing for years. Another idea is using pneumatic springs to handle most of the mass of the valve, and having the solenoids apply the differential force needed to open & close it.

"And,bikes now have rev-limits of 17 000 + rpm as stock...even seen Nissan RB26DET 2.6-litre straight-6 engines doing 14 000 rpm,so it's not the poppet valves that's restricting them,at least. "

No, it's more of an issue of varying the valve-lift, timing and duration such that it's optimal at each RPM-range. Over 20-years ago, Honda came out with the NR series bikes in endurance racing with 8-valves per oval cylinder. The thing revved to 20,000 easily. The street version was de-tuned to about 16,500rpm or so.

GlenL

The company I work for makes test equipment for the auto industry, mong others. The 48V effort appears to have peaked and is subsiding without happening.

The purpose was to power the ever-increasing electronics in the car. At 48V there's less current needed for the same power (W=IV, donchano) The industry now thinks that there won't be more mechanical stuff added (what, no power vanity mirrors?) and that the computers and such that are constantly powered are reacting prepdictably to Moores Law and getting smaller and taking less power.

Now if they add personal video screens and massage chairs, then it may become a reality.

The installed base is fairly big for 12V batteries, chargers, testers, accessories and such. I'd bet it could be pioneered on high-end cars as a differentiator. "The new Lexus with four times the power."

Maybe someday...

Reminds me of the Wankel engine. A big buzz in the '60s for that. Now it's Mazda with, what, one car? Just hard to make it seal reliably and cheaply. Sorta like the rotary valve.

GOBOGIE

That picture looks cool!

Curt911

Rotary valves have been used extensivly in 2-stroke motors, other than the seal life issue I see this design as very effective the rotating/moving mass is way down compared to coventional vlaves. looks like a no-brainer to me, I bet we see this develop into something soon. Even if the seals only lasted a race or 2, with the small amount of parts involved it would be worth it for the performance gain!

2BWise

Hell...It'd be worth it just to not have to worry about valve/piston interference

Mighty Shilling

I had a friend suggest I put one of those on the 924S... He said that, and individual throttle bodies per cylinder would make a very noticable increase in power....

porschefig

and a very noticable decrease in your wallet

Mighty Shilling

Yeah. no kidding! Apparently the "camshaft" on this engine takes considerably less horsepower to turn, and allows for better breathing in the engine, so it's insane the benefits. I may have to look into that...when I'm a millionaire...

Geo

Yes, but they are rather different in a 2-stroke.

tomc_85.5_944

Aprilia is racing pneumatic actuated valves in their bikes right now.....
Along with most of the F1 field, IIRC.