With the new N54 engine (not being completely new) and two turbo-chargers, BMW reaches back to an all aluminium crankcase (my guess is with grey cast cilinder liners) and is not using the R6 engine with a magnesium-aluminium crankcase.
I was wondering why that is?
Is the R6 crankcase not strong enough? Does it crack in the upper cilinder region, because of higher pressure caused by the turbo-chargers? Or does the engine just simply blow to peaces because of this higher pressure?