cleaning up the slant six head

I would also like to better understand how much a non-forced ( ? ) air induction will help on these little engines.

I see alot of you guys have come up with ingenious ways of modifying your air cleaners so that there is a pick-up located at the front of the car somewhere behind the headlights or in front of the grille.

I am assuming this is the same theory behind turbocharging....the more air in the more fuel it draws with it but one thing I am still not understanding is why does a larger amount of fuel/air that is entering the cylinder have an impact on the engines performance?

I mean I have read that the more fuel/air that can be shoved into the cylinder the better from a performance stand-point but I am not clear why. ....Is it because as more air/fuel that is trapped within the cylinder the compression within the cylinder ( compression ratio ) increases and so there is more boomboom when the plug fires?

More boomboom = more force = more power makes sense to me but I would like verification that I am working this out properly.

Also I understand ( unless I am mistaken ) that at higher engine speeds there is a certain layer of dead air that encapsulates the vehicle surfaces so how does this play into the scenario of one of these external pick-ups that guys are mounting.

Lastly I cant help but to wonder how one of these pick-ups assuming they are indeed drawing in more fuel can affect fuel mileage. Fuel mileage is a big factor for me. I do not want to make mods that will drastically affect my fuel mileage negatively.

I am possibly off on my thinking that the more air being drawn past the carb venturi is drawing in more fuel.....possibly it is a question of better atomization in which case I can understand the interest as I know that the fuel particles will burn within the cylinder much quicker/cleaner ( less waste ) if the fuel is atomized better.