I’m under the impression parts support for the, lisence Rolls Royce built, O-240 is non-existent. Hence, the reason many O-240 powered 150s now sport O-200s. Is this correct? The IO-240 is still being produced.
The O-240 weighs about 30 more lbs than the O-200. But was built for higher compression for higher octane fuel. I read an article about running an O-200 from a C150 on a dynamometer. With the Cessna 150 red line and a Cessna TCDS McCauley propeller, 87 HP was produced. I think that’s the typical HP Cessna 150s are producing. The O-240 book HP is around 125/130 HP. I think that’s the sweet sport for the 150/2 airframes. Good climb/fuel burn/CG.
I can’t find my single engine Cessna book. But the author mentioned that spin and aerobatic characteristics became poor / dicey with extra weight foreword of the firewall. Hence O-320 STCs prohibiting spins. (Maybe a great STC for Poobs?) However, I have zero O-240 experience. I’ll try to find the quote from the Cessna book today, unless someone can find it first. Busy day.
If I won the lottery, I’d persue a field approval for an IO-240 conversion. With a lighter PC680 battery, lightweight starter, etc. to get the weight very close to the O-200A.
