Andy, Greg.
This thread seems to be kidding somewhat, maybe the lasting effect of new year eve. Time to understand that we are NOT dealing with diesel motors at all (apart from some approximate exception of specially made engines and of the REALLY EXCEPTIONAL Eisfeld 10cc I saw somewhere in this site - why de Vries did not make a copy?).
WE ARE DEALING WITH HCCI ( HOMOGENEOUS CHARGE COMPRESSION IGNITION). They LACK of the main element in a diesel, the injector, or , more exactly, of the INJECTION phase, that allows diesel to be......diesel!!!!!!!!!!!!!!!!!!!!!!!!
So more humbly if someone intends to say " I understood and I know", he MUST know that HCCI is THE MOST UNKNOWN ENGINE TODAY. On the opposite, two stroke diesel engines are the more well known and biggest engines made today, more of 100.000hp of power, but they are NOT HCCI at all.
The HCCI cycle up today is subtly escaping both modelling and experimenting. None knows what a sort of fuel to use, and none can foresee what its future will be. A HCCI may be two or four strokes, but it remains EVER a HCCI. It is almost a miracle that model "diesels" run since none ever referred the true temperature and pressure cycle in a real cylinder, in starting or running conditions. So the matter is open and by sure capable of improvements. By this point of wiew some "ingenuity" is needed, but ingenuity is not all . The experience may appear ingenue, not the purpose neither the underlying theory . When the balls falled from the tower, the principles of the mechanics were clear in the mind of the experimenter .