I would love to see this project come to market, but its unlikely to do so with any of the existing or soon-to-be launched 4-stroke diesel engines...they are simple too heavy. If they do use any of the existing diesels then it will be a very expensive helicopter (in R44 terms).
I have spent a lot of time over the last few years looking in detail at all of the realistic engine options for a helicopter of this weight and the existing diesels simply don't work in helicopters. While on the face of it some of them appear to look comparable with Lycomings, by the time you de-rate them enough to be reliable they are very heavy. The 4-cylinder SMA engine is unlikely to ever be released above its current power rating as its reliability drops off very quickly above the current design point. The 6-cylinder unit will offer more power, but will be heavy and expensive.
Similarly they are claiming, 1235/2500lb =49.4% useful load out of a piston powered helicopter! Many of the turbine machines don't achieve this! Robinson and Guimbal are at around 40% with relatively light Lycoming engines. A suitably de-rated diesel engine will be significantly heavier, as will retractable landing gear.
It is theoretically possible to have a diesel engine that is light enough to work in a helicopter, but it wouldn't be the same configuration as would be used in an aeroplane and hence they would need to develop it themselves.
If they move forwards with this it will likely end up with the Lycoming IO-540-AE1A5 (R44 Raven 2's engine) or similar and a 1000lb payload.
Similarly, with all the resources in the world, they will not be ready in 18 months with the technical development they are proposing...maybe in 60 months.
Good luck chaps, look forward to seeing it flying.
CRAN
