I'm already thinking of a PP engine. By the looks of it from PL's tests it
makes about the same power as turbo, without the weight and more simple?
I don't know how it will compare at altitude?
Buly

 

Buly,

 The PP will lose power at altitude like any normally aspirated engine. If you are looking for near sea-level power at altitude you need a turbo. If you are looking for good takeoff performance a NA engine will be fine. The PP engine IS much simpler than a turbo engine. There is a lot fewer parts that are failure prone starting with the turbo itself.

Bill Jepson