ORIGINAL: MajorTomski
Why would a Fok D-VII call for an inverted engine? The original airplane has the prop shaft at the bottom of the radiator, an inverted engine would have the cylinder sticking out of the bottom of the cowling in a Most unscale like manner.
This is correct, the D-VII prop/crank is low or at the bottom of the cowl. When I built mine I had to mount the engine upright to get the prop in the proper location.
Inverted four strokes are easy as long as the tank is mounted slightly low so they don't flood or vapor lock. When it's time to tune the low end is just adjusted a little on the lean side. Pumped engines have to trouble at all. I also just run 15% fuel in all my glow engines, YS and OS.