| Author | Message | ||
     Shazam |
How fast could one of these tractor motors spin with pneumatic valves instead of the pushrod set-up The technology is proven in Formula one racing. could be the next "First on a production bike" offering from Buell. Talk about lightening the powerplant......no cams, no pushrods, valvesprings, rockers.....just solenoids and compressor? I know I am fantasizing, what do you all think? Is it only me who envisions sitting on the side of the road telling the inline fours that stop to help......"I ran out of air"  | ||
| Reepicheep |
I think our relatively long stroke engines are pretty close to the limits with piston speed anyway, even if the valves could be helped. You could go to a much more oversquare stroke, but you would then loose all your low end torque, and would still be at a real disadvantage to the 4's. Cool technology though. | ||
| Shazam |
damn, I forgot about piston speed..... still thinking variable valve timing, better cylinder fill, lighter componentry..... just daydreaming.................... | ||
| Rex |
see motorcyclist magazine this month for the KTM gp bike////REX | ||
| Blake |
Despite popular misconception (I too used to believe as you do), pneumatic valves do indeed utilize conventional cams. The "pneumatic" part only replaces the springs. | ||
| Kenb |
and as I understand it the F1 cars use a total loss system. There is a nitrogen tank onboard that is topped off during pit stops. The pressures needed are pretty high, thus unpracticle for casual use. F1 engines have a life span of 200 miles or so they are pretty stressed at almost 20000 rpm | ||
| Benm2 |
I think the new vette engine uses variable valve timing, on its pushrod two-valve motor. (05 model year) Its only got one cam to worry about, versus the Buell's four, so its a little easier mechanism-wise. | ||
| Djkaplan |
It's only a matter of time before totally active valve timing and lift is feasible. Before internal combustion engines become a thing of the past, we'll eventually figure out how to squeeze the most amount of efficiency out of them. | ||
| Jmartz |
I read of a solenoid actuated valve motor with no throttle plate. Active control of lift and duration took the engine form idle to redline. Pretty cool if such technology would become feasable for street use. No cam on this one. | ||
| Shazam |
Blake, thanx for the heads up. I haven't been exposed to the technology in the least. to bring up another ingenious device for feeding an engine....has anyone else ever seen the rotary valve design? I saw a program some time ago where some guy was testing a set-up on lawnmowers or some such small engine. It consisted of a gear driven (rpm following) disc atop the combustion chamber that had slots cut in it which were only exposed during the relevant portion of the cycle, the slots acted as the valve opening. The whole thing (valve train) had one moving part(the disc)! | ||
| Captainplanet |
Shazam, A lot of 2 stroke motors use that rotary valve design. As least they used to. I haven't been into one in while. Other 2 strokes use reed valves that get pulled open by the engine vacuum. | ||
| Rocketman |
We've covered this rotary valve thing recently. Rotary valve on a two-stroke is nothing to do with rotary valves on a four stroke. Not even remotely similar. Jose, I think you speak of Lotus. They have designed a motor that uses NO cam what so ever. Rocket |
