Is this possible ?
QUOTE (SlOoT @ Sep 6 2007, 01:15 PM) <{POST_SNAPBACK}>
Oops hit the wrong button, I would say no way with our heads... a great idea tho! No valve springs working against the motor and with positive action both ways the rpm's would be only limited by the pistons and reciprocating assembly. Could even roller tip both ends for less wear and drag! The hot ticket for the future would be electrical solenoids strong and fast enough to operate valves and an ecu can optimize the lift and duration according to rpms and throttle input. Imagine a 100hp single cylinder motor that could turn 17,500 rpm and idle like a new car!
Ok that is a little far fetched...
Ray
Ok that is a little far fetched...
Ray
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QUOTE (cannondale27 @ Sep 6 2007, 10:47 PM) <{POST_SNAPBACK}>
Suzuki and now Yamaha have gone to Pneumatic valves to compete with Ducati in F1 bikes.I am not sure what they rev to but I bet its close to 15,000rpm.Supposedly they were only getting 2hrs out of the valves when cams were tuned for topend power because of the steep angles needed.Cool stuff.
19,000 rpm on pneumatic springs. F1 cars are limited to 19,000 too, they used to run over 20,000 on occasion last year (before the technology 'freeze'). Most of F1 has been on pneumatic valve springs since before I was involved in the early nineties...
As far as I know the (new) Ducati moto GP motor uses Pneumatic springs too, valve train weight and packaging in the new V4 Ducati killed the Desmo idea in 'real' racing engines.
Most engines at this level will last (be 'lifed' to) six or seven hours, two hours is no sweat at all.
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Suzuki, Kawasaki, and Yamaha all use pneumatic vavletrains (Honda is using valve springs). However, Yamaha had an engine failure in it's first outing last week end. Poor Rossi. Ducati is still using the Desmo valvetrain, but I would be willing to bet that it's nothing like a road going Duc. Most everybody can rev their engines up to 18,500rpm, but since Moto GP has limited the fuel capacity to 21L most teams/riders choose to shift a little bit earlier. Did you see the race at Misano? BOTH Ducatis ran out of fuel before finishing the cool down lap.