Main Question or Discussion Point
in SI engines fuel/air mixture is compressed. The disadvantage is that one can't achieve high compression ratios. I was wondering if it was possible to compress fuel/air mixture to the maximum possible ratio without fear of ignition and compress a pure air mixture to very high ratios 25:1 and then mix the two together. The fuel/air mixture would ignite and burn at nearly constant volume. This way could we get high compression ratios with SI engines?