I built the Ringmaster because I had one way back in the 1960's with a Mc Coy 35. So I was thinking a new 35 would be OK but I guess the new engines have a lot more power than the old 35's? Should I be looking for new 19 or 25??
Modern engines have fantastically more effective "power" than old engines on a per-displacement basis. I have done extensive tests where an OS-20FP replaced a Fox 35 (a good Fox 35) and experienced dramatically better performance, almost to the point that no one believes me - until they try it themselves. The smaller engines run in a fast 2-stroke continuously, with 4" or less pitch to control the speed. The speed stability is *far far better* than a Fox doing a 4-2 break with a 6" propellor. And it won't shake the airplane to pieces.
The 20FP or "new" 25LA is also a bit too too much for a Ringmaster. The Ringmaster on the RSM Kit box top was built by my friend Jim "Uncle Jimby" Aron. This airplane has a very good finish and once received a perfect 20point appearance score, so it's not feather-light. It originally had a Veco 19BB with a 10-4 prop. That pulled it around at about 4.2 second laps on 60-foot lines. It was a little uneven-running, and we replaced it with my well-worn 20FP ABC. Then it went 3.8 seconds a lap! Jim eventually got the speed in reason with stellar performance with about a 9.5-3.5 Bolly.
Almost all the Ringmasters around here have used Veco 19's or OS20FPs. But one of the better fliers (and the one that set me on this experimenting with small engines) was a stock Sterling kit with a full opaque finish - and a OS 15FP! This airplane flew better than any Fox or McCoy Ringmaster we (David Fitzgerald and I) had flown at the time.
I would search the archives for "Brett 20FP 25LA" for more than you would ever want to know about these engines and much more. Also search "ringmaster elevator travel" and "ringmaster wing failure". One problem we have encountered is, once you get these very superior engines, even if you get the speed into the normal stunt range, is that the engine permits so much tighter corners that the wings can fail. Particularly if you are extra-clever and set up to build the airplane super-light.
And Evolution 36 can probably produce close to 3 times the power of a McCoy 35, and there's no practical way to harness that power on a tiny little Ringmaster with any commonly available propellor.
Brett
Topic: Evolution 36 (Read 1659 times)
