Don
I was able to find a more comprehensive photo of the engine assumed by you was the MAN mainengine alternative of the VIIC engine. The MAN submarine engine underwent a number of design developments from the early natural aspirated engine ,I believe in the late 1920this, via a mechanical supercharged version, to a Buchi turbo charged version in the 1930this and to the last turbocharged,intercooled high performing version having an output for a 6 cylinder version of 2000 bhp at 520 rpm. Really an advanced modern engine I believe introduced in 1944.
I do not think this last version of the MAN engine was used in a VIIC as 2000 bhp at 520 rpm would require quite a few alterations in both the Emotors, shafting and propellers etc.
However I guess the engine was developed for the new "Electroboats" class XXI all equipped with MAN 6 cylinder M6V 40/46 KBB being the last type of the WW2 MAN submarine engine.
Below I have a picture explaining why I assume your picture is from a XXI boat. The people are standing on a footstep attached to the engine (on the GW engine is a similar footstep which can be folded in) which fooled me to believe it was a smaller boat. Even if the airduct from the turbocharger and intercooler is not rounded as on the picture of the MAN M6V 40/46 KBB, I believe there are so many components similar to a MAN engine which justifies my conclusion the engine is a MAN M6V 40/46 KBB in a XXI boat of which I have no knowledge.
Tore