That is quite amazing.  Interesting to note that the combustion seems to be predominantly on the inlet port side, you would think that the piston rising would equalise the pressure and you would get a more even combustion.

Note this is not an Alfa engine and the engine shown has no valve overlap, although it dosn't show a complete cycle it shows the whole of the inlet valve opening stage and the exhurst valve is already closed before the inlet starts to open. The yellow flame is only the part of the combustion that has to much oxygen in the mixture, most of the combustion is should be a blue flame this is not very visable in the footage.