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Join Date: May 2003
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A new Continuously Variable Valve Actuation system
At www.pattakon.com a new Continuously Variable Valve Actuation system is presented, with working prototype photos, plots and animations (even stereoscopic ones).
Any engine, racing or normal, can be improved as the torque can be about constant from very low revs to the top allowable revs of the engine. Comments? Objections? |
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05-02-2003, 09:56 PM
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Irrationally exuberant
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Neat! I couldn't get the stereo stuff to work for me though.
-Chris
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'80 911 Nogaro blue Phoenix! '07 BMW 328i 245K miles! http://members.rennlist.org/messinwith911s/ |
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05-03-2003, 07:10 PM
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Location: Montreal, Canada
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Wow, that is amazing! opaia thoulia!
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Mike 03 996tt w/efr7163 89 Carerra 3.6 |
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05-04-2003, 07:19 PM
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Nice theary. I have thought about hydralically controling valve operation. Then you wouldnt even need a camshaft or the oil supply. Also you could adjust your valve timing electronically. Ahh what the future will bring. I wish I had an education in automotive engineering. I have so many ideas and no money to put them to use. I have a idea for brakes as well but I dont want to give up my million dollar thearies for free(LOL).
Kurt Williams
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Never drive faster than your gaurdian angel can fly. 82 SC w/965S eng and G50 6:1 hp/w ratio 72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles 65/66 912 1 owner 76k orig 01' Aston Martin DB7 V12 Vantage Coupe 6spd |
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05-04-2003, 08:11 PM
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Electronic ones will be better.
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05-04-2003, 11:38 PM
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Irrationally exuberant
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What's attractive about this one is it's simplicity and low cost.
-Chris
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'80 911 Nogaro blue Phoenix! '07 BMW 328i 245K miles! http://members.rennlist.org/messinwith911s/ |
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05-05-2003, 03:58 AM
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i believe international or volvo is currently testing their hydraulically controlled valves in over the road test trucks. IIRC the article i read mentioned that diesel vehicles where more suited for the current technology due to their relatively low rpm (4000 rpm max). international expects large economy/power increases with the new tech once real world testing gets the bugs worked out...
ian |
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05-07-2003, 07:39 PM
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Location: So California
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Electronic ones will be cheeper, more reliable, and more accurate in terms of performance. Price will come down soon, when it goes into production, just like electronic fuel injectors did vs mechancial injectors.
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05-07-2003, 09:03 PM
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Dept store Quartermaster
Join Date: Jul 2001
Location: I'm right here Tati
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Yes, Lotus claims to have a fully operational solenoid operated valvetrain in development. The valve is still closed by spring but lift and duration are infinitely variable. Very cool! My only question is what took so long?
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05-08-2003, 06:08 AM
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My understanding is that F1 designers have looked at (and away from) electronic valve actuation. If my memory is correct, they pretty much came to the conclusion that such a system would end up adding too much weight high on the engine when compared to the traditional camshaft driven system. Keep in mind the mechanical forces involved in cycling the valves over their full travel over 9000 times per minute (150 Hz). As far as I know I don't think that they're even using variable valve timing such as is used on production Porsches and Hondas. I believe that the cost and reliability trade-off's didn't justify going there.
I can only assume that they can get most or all of the same benefits with the existing variable length intakes and good old fashioned ignition mapping. It will be interesting to watch the F1 cars again this year at Monaco. I seem to remember seeing David Coultard's Mercedes pulling strongly from about 6000 RPM up to 18000+. If you ask me that's one heck of a rev range to try to improve on without adding weight. I have to say that at first blush the system described in the above link looks pretty clever.
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John '69 911E "It's a poor craftsman who blames their tools" -- Unknown "Any suspension -- no matter how poorly designed -- can be made to work reasonably well if you just stop it from moving." -- Colin Chapman Last edited by jluetjen; 05-08-2003 at 08:26 AM.. |
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05-08-2003, 08:05 AM
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Don't the F1 cars use Pheunumatic, ie nitrogen air controled, valves? Thats a piston at the end of the valve that is operated by compressed nitrogen, no springs.
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05-08-2003, 11:33 PM
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Jack;
The F1 systems use the cam to push down on the valve and the pneumatic system to close them. So you're right, no springs, but there is still a cam, and it certainly isn't continuously variable -- at least according to the latest reports. 
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John '69 911E "It's a poor craftsman who blames their tools" -- Unknown "Any suspension -- no matter how poorly designed -- can be made to work reasonably well if you just stop it from moving." -- Colin Chapman Last edited by jluetjen; 05-09-2003 at 08:18 AM.. |
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05-09-2003, 08:10 AM
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Then again F1 cars have no NEED for a variable cam timing as they always operate in the upper range, ie no need for low range torque. If the F1 cars needed to operate from 1000 RPM to 18,000 RPM then they would need the variable cam. But they don't. They only operate above 6,000 rpm.
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05-09-2003, 09:11 PM
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The Blue Pheonix
1969 Porsche 911 2.7 
1969 Porsche 911E 2.0 E
