Ahhh...
If that's what you mean by MTBF, I suppose you are correct that 8-9K hours would be a conservative guess.
If the hours are done correctly there would be metal testing at overhaul every 2-2.5K hours.
Flown and maintained properly, I would suggest that the majority of certs get to TBO. But, you throw in the inactivity, or ham fisted driver, or chintzy owner, and who knows. Same in the VW world, I regularly get tremendous wear out of my VW's many do not....but I change alot of oil, and drive it properly. 113,000 out of the original clutch so far on a VR6. Who says heel-and-toe is for the track only.
We will always disagree as to whether that PSRU was still a prototype. They were sold to customers, money was taken by Egg, and they were represented to customers as flying and tested.
I will say this, if I ever do a Subaru, it will not be an Egg for that reason. The lies, and half truths. I would have to committ myself to a roll-your-own approach. For example, he now claims 14 turbo H-6's delivered....totally untrue, not a single RV-10 H6-Turbo package has been delivered.
In the begining, I was totally attracted to the claims on his site....now as I sand every more of the tips and other finishing work, I am glad I went the easy route. Ever with a certified engine, the thought of a forced landing with a C/S prop on a 7 is a concern to me.
If I could ever find a cheap core, a 3.0 911 SC engine would make a cool conversion. But, I digress.