Hi Laurenne- I have an Ace 4-120 that weighs around 15 pounds and I put a RCV 90 SP in it. I have an APC 18-14 prop on it now and have tried a few other props also. It flies, but it definitely needs more speed and power to fly well. I should have known better than to put a 90 in a 120 plane, I suppose, but I had the engine (I bought it from you in Chicago) and it seemed to fit on the front of the plane so nice I just had to try it. Will a 120 fasten with the same bolt pattern and how much longer is it than the 90?. I made a nice cowl to fit this engine and it would be a shame to have to butcher it up. It would have been a little smarter to try flying it first, I know!
How much bigger prop does the 120 spin and how much more "zip" would I get out of it?
Have you considered making a bigger version of the CD type engine - like around 120 - 150 size? Will you be in Chicago in Oct. 06? How about throwing a few engines in a suitcase and coming to the the Toledo show in April?
Jim in Wisconsin