However, the efficiency gain is less than corresponding to the volume ratio, because the expansion is not truly adiabatic and burnt gas becomes cold faster because of exchange of heat with of the barrel diameter while sealing needs are proportional to the perimeter by the same pressure.
However, the efficiency gain is less than corresponding to the volume ratio, because the expansion is not truly adiabatic and burnt gas becomes cold faster because of exchange of heat with the barrel. The force is proportional to the square of the barrel diameter while sealing needs are proportional to the perimeter by the same pressure.