Rumbler kit from Minnesota Modeler. Great kit, perfectly fitted pieces and easy assembly. Sporting a Norvel .061 ame with in-wing bladder and weighing in at a hefty 5.8 oz. w/o fuel. Can't wait to get this one on a set of 42 foot lines!!   

Ray, that looks like it would truely be a blast to fly.  Hope it flies as well as it looks.  DOC Holliday

Hi Bill, this one is pressure, ame's mostly require either muffler pressure or a bladder. Have never tried crankcase pressure.  I actually have run a couple of ame's on balloons with a successful 4-2-4 , not really trying to ,  guess i just had the needle set just right, it was pretty impressive with these little motors on 30 foot lines like i fly in the backyard. In my opinion for stunt flying 1/2a's, balloons don't get the credit or the research and refinement they should. If the engine you are using does not require pressure i would much rather use a balloon than any hard tank i have tried. I am still researching this theory but right now it is 2 to 1 in favor of balloons. Still trying to find the right set up for the holding tank for up to 1 oz. Would love to find a way to use a thick baggie to hold the balloon on the plane instead of a plastic bottle. Still looking, that's what makes this a never ending search!, and fun!

Ray,

Thanks for the info.

Jim Walker came up with a brilliant idea for a balloon tank holder, over fifty years ago!

His RTF Firebaby used a simple molded canopy, that snapped onto the balsa fuselage right behind the engine mount. The hollow canopy held the balloon tank, with a small hole in the front of the canopy for the fuel line to exit. I don't remember what kind of engine runs I got with that set up, but it must have worked pretty well, as many of us have very fond memories of flying the Firebaby successfully!

The tank was a bit higher than most would like on a modern stunter, but the Firebaby flew mostly upright anyway, with that undercambered wing.

Bill

Clever.  Looks good too.