Rotax 912ULS Longevity in RV-12

I?ve been wondering about the 912ULS longevity. The RV-12 fleet is somewhere near 1000 planes so I think it is time to ask this question. In my opinion the 912ULS engine and the RV-12 make a perfect combination. That said I now have 220 hours on my early RV-12 SN120058. Engine runs like new. Oil consumption is less than a quart in 75 hours burning 93E10 fuel exclusively. Starts and runs like a car engine. No mixture or carb heat to fuss with makes it single lever control.

I will do all scheduled maintenance included gearbox, and rubber hose replacement as required. I change oil and filter at 75 hours with Aero Shell Sport 4 Oil.

Rotax has increased the TBO based on history of engines in the fleet. What I?m wondering is how many hours some of these engines are running in the experimental category based on acceptable condition inspections? TBO or beyond?

As mentioned previously, I have an early SN 12 with angled exhaust stack and close clearance between front of muffler and oil cooler. I don?t have oil temperature problems other than on a long continuous climb on a hot day. Temp easily settles back to green in cruise. I?m also still running original Evans waterless coolant with no problems.

Ducati voltage regulator packed it in at 100 hours and now running a John Deere AM101406 with a 2nd EFIS and no AP or lighting package. Everything is electrically happy.

Prop pitch is set per Van?s instructions and cruise speed and climb rate match published specs. Engine runs very smooth. I typically operate the engine at 5000/5100 with 120 mph cruise. Fuel burn is just shy of 5 gph.

This year I will add a Reiff preheat system during the annual condition inspection. This, in and of itself, should add to engine longevity.

So to summarize, I?m very pleased with the 912ULS/RV-12 combination and just wondering what other people think about life expectancy for this engine if cared for properly?


-

My opinion - -

2500 hours at least. I have 1,057 on mine. Nothing has changed since new. Uses a little over a pint of oil in 100 hours. I have only used premium auto fuel, no ethanol. I usually do not run much above 5,000 rpm. Might affect oil usage a tiny bit if you run at higher rpm's. Pretty solid engine. Carb floats and ign modules have been issues, but otherwise a good engine.

I have always been under the impression that the core Rotax 912 powerplant has been pretty well wrung out from a reliability standpoint during its tenure in the RQ-1a Predator. I believe that the Air Force has been pretty critical of reliability and serviceability of these engines for obvious reasons and general aviation had benefited from that. The same cannot be said for most of the Lycoming and Continental powerplants.

-larosta

At the ROTAX service course the instructor said it is not uncommon to open an engine for scheduled overhaul and find it in essentially new condition if properly maintained and operated.