[peterrr]

If the diesel was burnt before TCD your engine could ony run backwards
Condensation in a 1cm space with a pesrrue of 30 bars would be surprisingly fast I even looked up the average molecule speed (square root speed)
for c10h22 at 500 C (which is low for temperatures due to adiabatic compression).
Even these fat little buggers go at 9m/s =900cm/s. Let us define TDC as the time the piston has only travelled 1.5 % of the stroke from the top
stroke =0.5*(1-cos(CA)) then you see it lasts from -14 to +14 CA.

6000Rpm= 100Rps. time at TDC 28/360*10msec = 0,7millisecond
The average distance to the to travel 0.5 of a cm. I gues they can reach the cylinder head. And I even did not take into account the fact that there are lighter molecules in the mix which share the same vapour pressure.
You, better believe me ther is condensatio going on.
Or look at a truck on steep hill, Some soot will come out.