Thor, I used the 50/50 expression cos you mentioned "half and half", sorry, nothing really technical there

I have a fair experience with aviation piston engines (I was lucky enough to fiddle with 2 strokes and 4 strokes Rotax, Gypsy Major, Continental, Lycoming, P&W Wasp and lately I started to get acquainted with the RR Packard Merlin), but I am no engineer or techie, I am just a flier who's interested in knowing what's happening under the bonnet in front of his nose..

I am not entering in the merits of lambdas or mixture ratios because they're peculiar to the engines and aeroplanes (and as you said 100 posts wouldn't be enough), all I can tell you though is that yes, in theory a direct injected engine like the DB could be more "mixture efficient", although carb engines are handled according to strict parameters, so you would hardly notice any difference in the flames colouring.. if Oleg managed to implement a flame colour changing according to mixture values then this would be a boomer, cos we'd be able to adjust our mixtures by looking at the exhausts and might also be able do diagnose engine problems (i.e. red exhaust flames and sparks coming out would mean a bad, bad day.. or in case of radial engines, where the exhausts are normally connected via a ring exhaust, an intermittent flame from the main exhaust would mean misfiring cylinders etc..).

Come on Oleg, this is quality material we're delivering you here!