Same Song...
NSI, Crossflow, Eggenfellner, Maxwell, Geared Drives, JPA, Vesta, PowerSport, Viking. What do all of these conversions have in common?
1. Not one had even 500 hours of flight time on one example without issue before being released to the public for sale. Some companies did a better job than others with regards to testing but the fact remains that none have really properly been flight proven with multiple examples for say, 1000 hours each as one would expect to validate reliability of the entire package. Really a couple hundred hours on one example is essentially meaningless.
2. Few if any have managed to match the reliability, weight, fuel burn and performance offered by the traditional engine choices.
While there have generally been few issues with the core engine chosen, there have been mild to serious issues with each one with regards to the whole FF package- fuel, ignition, gearbox, turbos, cooling etc. These are just as serious in most cases as a hard engine failure. In some cases the packages have been complete jokes, lasting only seconds or a few hours before failure.
The posts here really sum it up:
1. Don't be the first to line up for a package that is not substantially flight proven. That pretty much leaves you right back in the Lycoming and Rotax camps. End of story for most people.
2. If you learn nothing from previous experience and treat new customers poorly, you are destined to repeat the same business failures again. The internet will slay you with bad press pretty quickly.
3. Not testing the product properly and extensively before release will always come back to haunt you.
4. Publishing vague or unsubstantiated weight and performance figures for a FF package will come back to haunt you.
Sorry to say but the vendors and builders with stars in their eyes never seem to learn...
Yes, the Lycoming and Rotax are expensive and still have the occasional issue but you are getting a product that has been massively proven in return and for most people who just want to fly their aircraft, these are really your best choices.
Auto conversions can be very reliable as proven by some one offs and ones like the RAF Subaru Gyros which have tens of thousands of hours collectively with an excellent record but the record by FF vendors has not been good at all for the most part.