This a 912 that was developed to fly at high altitude, it has custom fuel injection and most importantly a piston oiling system that extends engine life. This can easily be converted back to a stock configuration if required for your application as I have many of the original parts that were removed before the engines were ever started. This was a new engine that had custom parts installed and then was tested in an altitude chamber but never flown.If you have questions please call 1-540-636-6110 THANKS