Rolls Royce O-240
 

Hi fellas, can anyone tell me what these engines are like and anything to watch with them? Also will they run on mogas?
Cheers, Zach.

Produced at Leavesden by Rolls Royce by mating 0-360 (I think) pots with 0-200 crank.
Ran just as sweetly and reliably as the 0-200 and made a great improvement to the performance of C150s; pity it didn't come in time to be fitted to the Beagle Pup. More powerful than the dreadful Lycoming which succeeded it in the C152.
Don't know about Mogas; I thnk they were meant to run on leaded fuel.

Not sure if I'd say the Lycoming O-235 in C152 was dreadful...

But back to the OP.

I have a bit of experience with the RR O-240. There were quite a few of them in FRA150 Aerobats here in Ireland. The issue with them is there are no replacement crankshafts. Once you're out of metal on the shaft your out of luck and your plane is retired or re-engined. A prop strike, and your SOL. I had a O-240 core and the guy who bought it had tried 80+ leads to try get bottom end parts for his. There is a chap in Netherthorpe who is the specialist in them, but he wont sell you the crankshafts he has in stock as he needs them for his fleet of FRA150's.

RR O-240 are quite sweet engines, but in principle doomed. the few remaining spare parts will allow only a few engine to go through the next OH and the rest is scrap metal. So, if you find one, get it only with a lot of hours left on the engine and calculated value to zero at engine EOL.

Great Engine and the C150 O240 Aerobat I flew last month went up like a rocket ship compared to my 0200 engined C150, there was no comaprison, however I was only flying the 0240 Aerobat as I fitted a new engine to it, and the aircraft had been sat for around 10 months without an engine as the owner couldn't find a crank.

A nice zero hour one, on private use is what you need to find.