Originally Posted by cmac2012

I've fantasize before about what sort of valve operation would be workable with some sort of auxilliary force and activation. Existing valves need a certain amount of torque to move against those springs. I imagine any sort of cam-less timing would use electricity to time and activate the valve (duhhh) and perhaps to do the actual work of moving it - electromagnetic solenoid (redundant) perhaps. Or maybe electrical signals could time the opening of a gate to hydaulic pressure.

You mentioned rotary valves and that's a thought I had. But it's a scary propositon. How you going to keep the seal good enough while opening and closing those things flawlessly enough? At 4000 rpm, each valve opens and shuts 33 1/3 times a second.