Thank you Mike, Zathros and Boris
Well, this is a critical stage in the process and i have a decision about the engine...
It's going in!
I thought a lot about it and found theoretical solution that serves both goals:
to keep the integrity of a hall and to try to expose to the most this beautiful engine.
Option with engine beside the tank - no go. Too fragile and to complex.
Option to build another one for the side - no go. I don't have another half a year for this

So, in theory i want to make removable top, like i did in Pz.Kpfw.III and then the engine will be exposed enough to examine it from most sides, like in this stage on pictures below.
In addition, there some big openings in engine bay from the side and on top, so even with closed top it will be seen good.
I was a little worried in process of putting it in, since this model is to complicated to make little mistakes and i hope i placed it in right spot and everything will come together nice, in later stage...
Overall, engine set easy in to place, though i was in need to temporary remove and put back later two fire system hoses, that were in the way of big bottom tube.
The partition also entered well.
IMHO, the engine looks great inside, as it is outside