Bill, I know someone who is in the middle of an IO-550 Conversion to a Cessna 170B. That is a 300Hp conversion, with the possibility of cranking even more out of it. Possibly as high as 360 HP! With a three blade CS prop.
It is an STC approved conversion, and all reports are that the ones that are flying are a real handful on landing and take-off (particularly on take-off). I don't know what the long term stress on the old airframe will be. But the torque with the long narrow landing gear is apparently something to behold. They really like to head off into the woods (kind of like my slice on the golf course).
In a similar vain, when they made the KC-135R conversion from the KC-135E, the CFM-56 tipple bypass engines had so much more thrust than the originals that they had to D rate them to about 65% as full power was over-stressing and cracking the airframe. Two CFMs had about 50% more power than all four of the original turbojet engines on the 135.
I'm not saying that a 180 HP engine on a Cessna 150 is going to pull the plane apart, in fact I'm quite certain it wont but I would expect it to have some handling quirks and expect that a 150/180 will be different than a 150/150.
Don't know, haven't flown one, would love to try it, am curious to hear from those who have. Thus far we have only heard from one. I KNOW there are more in the club who have flown the 150/180 TW however, looking forward to hearing from them.
