Comment Re:Cam shafts work without the battery (Score 1) 383
As another poster mentions, pneumatic valve actuation in motorsports is not to meant to do away with fixed cam timing -- there's still a conventional camshaft present. In F1, MotoGP and similar sports, pneumatic valves are there to be able to run engines at higher rpm (> 18,000 rpm) without valve float, which is what happens when you rely on spring-actuated valve return. In sporting applications, it's not so bad to have fixed valve timing, so long as you have fine control of ignition timing and dynamic fuel maps.
Camless engines have been tried by BMW and maybe others in 1980's using electromagnetic actuation with computer controlled timing. I believe it didn't work well with the manufacturing and materials of the time. Another approach was tried by Lamborghini with a mechanical camshaft that had variable lobe profile from side to side and the camshaft could slide back and forth with servo motor that was computer controlled to maintain a match between effective cam lobe and rpm. Would be very interesting to see a system like that pushed further with modern electronics and metallurgy.
And of course we already have total cylinder shutdown on many production vehicles. I think this is generally done through hydraulic valve lifters that can be manipulated by cutting off oil pressure and closing the valve (no air or fuel gets in, but maybe a secondary compression release valve is opened).