Lighter valve springs for better mpg?

[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.

[dcb]

I like the solenoid driven valves for maximum timing flexability myself, at least as a possible bolt on where you can, i.e. throw a switch and go into atkinson cycle, or many many other possibilities. Shouldn't be too much harder than replacing a cam for an OHC engine and installing a custom valve cover.

Probably not a huge market for it though, and a real pain if you have inspections.

[Christ]

They never pop any part of the engine for inspections, anywhere in the US, that I know of. If they did, there'd be liability problems for the inspection agents.

(Something goes wrong shortly after an inspection, must have been the retard inspection agent's guy) (Something along those lines).

When I mentioned the valve in piston design (for that instance, for the illustration) I was thinking more of a constant speed/load engine. Not that too many of those really actually exist, but if one were inclined to build a generator that always ran at a specific speed/load (load cells, whatever) until it wasn't necessary (load based switching, something to that effect) it could always run (reliably) in it's max efficiency.