[Christ]

Originally Posted by dcb

All I'm saying is that you can "push" a cam to some degree and get energy return from the springs. when you get towards the base circle of the cam I'm sure it becomes a bit like trying to drive a worm gear in reverse, but not a lot of reciprocating going on there. And when the rpm goes up (and/or you have big clunky valvetrains) the momentum of the reciprocating valve/follower/etc increase and you need sufficient spring tension to hold that mass to the cam under the anticipated operating conditions.

If you are never, never going to exceed 1/2 redline, then maybe you can get away with springs of 1/2 tension. If you lighten the reciprocating components, you can reduce the tension. You also have to pay attention to spring harmonics when designing valve springs FYI

That illustration above - is that a valve in piston design?

There's something I've looked into before, to enable the head to be a flat plate that is just bolted on. No cams, no timing to set, etc... That'd be fairly awesome for a direct inject engine, I'd think, with critical valve timing being controlled directly by piston movement.