Will Camshafts Soon Become Extinct?
No offense intended, but you are misinformed.
http://www.valeo.com/automotive-supp...ng/en/pid/1317
http://findarticles.com/p/articles/m...7/ai_n15865061
The design Valeo's working on uses springs to open the valve. They could use an em actuator on opposite polar ends and alternate the switches so a spring wouldn't be necessary, then it would be possible to open the valve much faster than a spring would allow. It looks like there's enough room in the pick if it's to scale. I suppose they're not concerned with it in an economy car; infinitely variable valve timing is still achieved. IMO it would be cool to do it just from the technological stand point.
Last edited by greysteel_M6; Feb 2, 2007 at 02:58 PM.
http://www.valeo.com/automotive-supp...ng/en/pid/1317
http://findarticles.com/p/articles/m...7/ai_n15865061
The design Valeo's working on uses springs to open the valve. They could use an em actuator on opposite polar ends and alternate the switches so a spring wouldn't be necessary, then it would be possible to open the valve much faster than a spring would allow. It looks like there's enough room in the pick if it's to scale. I suppose they're not concerned with it in an economy car; infinitely variable valve timing is still achieved. IMO it would be cool to do it just from the technological stand point.
OEMs must be all over this by now. Heck DOD (or whatever the different manufacturers call shutting down half the cylinders) only nets about 8% better fuel economy in real world testing.
Perhaps these are just claims. As of Nov 05, about 15 months ago:
"Thierry Morin, chairman and CEO of Valeo (www.valeo.com) says electromechanical valve actuation is--at most--16 months away from full production feasibility."
' "The diesel-like clatter is gone," he claims, "and the system is designed to fit under current valve covers." This has been accomplished through the use of small damper springs that soften the deceleration of the valve at each end of its stroke.'
So much for instantaneous valve action.
Could this system work? Probably. Will it give the 20%-20%-20% results promised? I'll be watching AutoWeek or Ward's for breaking news of this coming to market.
Count me among the skeptics.
The variable valve timing in overhead cam engines gets you part of the way there, but is still limited to usually two different cam profiles. So there is still some “optimization” left on the table. These variable valve events have allowed lowly 1.6L engines to make 160 horsepower and 4.2L V8 (Audi) to make 420 horsepower and still accomplish reasonable gas mileage and have great manners. With that in mind, imagine what could be done with infinitely-variable valve events. All of us would be driving our 5.7L V8s that made 600 peak horsepower and still got 25 mpg city mileage and were as mild mannered as a plush Mercedes.
Combine all that with a CVT and you really start seeing some huge gains being made in internal combustion engines. It’s exciting to think about. I agree with 1CAMWNDR. The infinite abilities of such a system almost require a number of “presets” for the user to choose from. Towing, cruising, max efficiency, max power, and max torque – they would all be attainable from a single-size engine. You would basically be choosing the engine size based on your required maximum output (say 500 horsepower or 500 ft/lb torque) and working backwards on everything else from there.
Now would somebody please design a reliable system and get it into production ASAP!
Didn't it take something like 30 years for dual camshafts to become affordable and we still don't have them affordable in V8's yet. <- that's actually a question btw not just a statement



