Originally Posted by kerry

It looks to me as though the mixture does a pretty good job of spreading around, so the concentration of flame around the valve can't be explained by the mixture sticking around the valve. Could it be that liquid fuel adheres to the valve, causing the additional flame around the valve. I'm surprised that the explosion is not more volatile in general.
Is the sequence posted edited at all? The piston doesn't seem to rise to tdc enough to account for 4 cycles. Am I missing something?