I've been thinking of compression ratio, fuel ratio, and infinitely variable valve timing.

As I understand it, there is an ideal fuel ratio, which the O2 sensor gives feedback to maintain.

I saw a show a little while back where s guy is developing hydraulic valve actuators, electronically controlled, which not only give infinite valve timing, but allow the lift profile to be infinitely modified. This also allows complete removal of the camshaft and its parasitic power load.

Static compression refers to the volume ratio of cylinder with piston down, vs. Piston up. About 8:1 is stock, mainly for emissions requirements, anything over 9:1 and you have issues with detonation, but the power increases.

Now to tie it together

Isn't the end result of compression ratio pressure? Seems to me, the piston diameter and stroke are irrelevant, the resultant pressure is decided by the compression ratio. BUT, if you don't allow the cylinder to achieve a full charge, the end pressure will be less. Hence with infinite valve timing, couldn't you control the cylinder pressure, allowing the engine to mimic a low compression engine, and of course let the computer adjust fuel and timing.