Would this reduce pumping losses?

[ar5boosted]

Originally Posted by cRiPpLe_rOoStEr

I'd rather try something all-mechanical (though it could be servo-actuated and fully-integrated to the cylinder deactivation), operating in the opposite principle of a Jake-Brake.

That's what I was thinking.

It would be a mechanical valve, but having some type of hydraulic/electrical actuator to control the valves. Which would look like standard inlet or exhaust valves only on a much smaller scale.

Maybe such valves are already being made for r/c planes or small engines.

The actuator/control-mechanism would obviously be on top of the plug.

[BLSTIC]

Alternatively you could retard your inlet cam under light loads, reducing the pumping losses by having two 25mm holes in the top of the head until the piston is half way up the bore. On many engines no extra hardware would be needed and you wouldn't have the engine management hassles brought about my having metered air being vented.