Auto engineering video series.

MadChemist

Pretty good episodes. Keeps it pretty basic. Doesn't talk about combustion efficiency due to the increase of O2. One thing that could be argued is that while STP is approximately 14 psi, due to the increase in volume from the piston traveling down the combustion chamber, the chamber is actually at a lower pressure.

Edit: Okay, it depends on the time (valves open/closed).