Hi,
I've been following the diesel issue with interest. Break even on the SMA seems to be about 500hrs (C182), thereafter you keep money in your pocket. I also found a interesting engine on
www.dynacam.com. Its a diesel, weights the same as a Lyc. 360 (about 300lbs) same power 200HP double the tourque with an 18 inch diameter (round like a turbine) FAA approved for Helicopters, busy with fixed wing. Reason for this is for a fixed wing you need to approve the prop also.