It's such a wonderful project, as I recall there was a Mercedes V8 diesel that was also previously used as an aero engine. I was considering buying one that I found at one point up for sale on Craigslist here in the sw US. It was a technical school unit that was up for sale, sorry I didn't jump on it at the time.
As is always the case there are pros and cons for axial flow versus eccentric reciprocating engines. With which we can lump in radials in the same category.
High compression ignition compression engines run lower EGT's which is good, turbo charging gives the ability to introduce more oxygen for combustion and develop more power. The turbos must be huge.
To achieve the correct stoichiometric ratio on a diesel more air (oxygen) is required than fuel per stroke - this is why a diesel has higher thermodynamic efficiency than a.gasser. i.e it uses less fuel per stroke.
I love the idea of using a compression ignition engine, but would be more inclined to consider two in-line V6 diesels with a coupling between the two with a mechanical bypass to the prop gearbox to allow for actual redundancy. Respectfully I would not wish on my worst enemy any type of reliance on the other bank of an engine that is mechanically attached to my good portion of the engine to get me home. Change my mind.