Engine ID and carb questions.

There are 2 variants with and without muffling. Throttle ring exhaust restrictor is very effective. I used one on a Black Widow in the late 1970s. One with a muffler works well too, if you need to remove the bark off the engine to fly at some locations.

I had its predecessor, the R/C Bee, an interesting late 1970's engine. Had a larger fuel tank than the standard 8 cc one on Golden Bee's and Black Widows, but a silicon cover that burbled to provide muffling effect. I flew both with and without the silicon cover. RPM's were a tiny touch higher without than with, but still had decent power with.

Sure Start ought to be a blast with that Cox throttle muffler.

So guys, I have heard 2 answers of what it could be. On my end I am mostly into knowing what I have, learning as much as I can about it, and running the s*** out of it!


so functionally what is the difference between the dragonfly and sure start engines?

-Rob

I would have to agree with Overloard. It’s definately a front and top end from a Dragonfly.

This throttle/muffler combination was used on R/C Medallion .049 and the early Cox GTP Nissan car.

I've got a Medallion .09 R/C, which has the later exhaust throttle muffler. About the only caveat is that the piston has SPI, so the output is slightly decreased by inducing inert exhaust gas instead of a fresh air charge slightly diluting the air-fuel charge. But if you want an engine that is lightweight and narrower to fit a half-A plane with more power, it still is a good choice IMO even with this deduct.

The Dragon Fly and earlier R/C Bee don't have SPI, so muffling will be more effective without hindering power. Cylinder was derived from the earlier QZ without SPI and Babe Bee 5 cc tank that later morphed to the QRC with 8 cc tank without SPI and without throttle.

I'll probably run it with just the ring, it seemed very effective. When I get back from the slot car track tonight, I'll post pics of the 2 carbs that were with it. One looks like the standard cox one and the other looks aftermarket.

-Rob