Grob Engine
As i do not have a Vig to look at can someone tell me if the G109 engine has a VW base (unlikely to be Porsche).
What have been the actual real engine issues (not including carb icing or fuel line related)
Who maintains or overhauls those engine in the civvy world.
I think Limbach are still around (direct drive units) i not think anything with a g-box would be the answer.
For ATC use you need something that is as SIMPLE as it gets. Reliability is quite often a question of proper simple cooling and not having an engine installation that looks likes a robots intestines.I am a big fan of VW based units as they have prooved themselves for decades and have a huge aftermarket support.