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Engine basics => Engine set up tips => Topic started by: Joe Messinger on August 15, 2006, 07:55:09 AM
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I have a couple Ringmasters that I fly occasionally just for fun but haven't yet found a fuel tank that is satisfactory.
The space between the leading edge of the wing and the back side of the engine is so limited that most 3 oz. tanks I've tried barely fit. The outlet is too close to the engine and causes the fuel line to bend almost shut. I've tried clunk tanks with offset outlets but the fuel pick up line on these small tanks doesn't flex very much because it's so short. The clunk just hangs there in the center of the tank.
I'm sure there's a tank set up that works well as there are lots of Ringmasters out there flying around. I just haven't found a tank that's suitable yet.
Any advice would be appreciated.
Thanks,
Joe
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I have an RSM Ringmaster and their 4oz tank fits just fine behind a Fox 35 or a Magnum 25.
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What's the distance from the L.E. to the back of the engine on your RSM Ringmaster? That distance on Sterling Ringmasters is 3-1/4".
The shortest 4 oz. tank in Brodak's inventory is 4". Even in 3 oz. tanks, 3" (wide wedge) is the shortest. Doesn't leave any room for the outlet tube and fuel line if you set it up on the venturi centerline.
I once had a 3 oz. tank that came with a Top Flite Flight Streak ARF. On that tank, the outlet exits the tank then turns down 90*. I can't find any of those tanks in the catalogs. Maybe I can modify something. Perhaps that will work?
Joe
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I built the tank for my last Ringmaster for that reason. It is a uniflow, 2" wide, by 3" long, and 1&3/8" deep. I ran the feed tube out the side of the tank, just below the "v" so that it is behind the front of the tank by about a 1/4". Seems to work well with the McCoy 35, except for a slight richening toward the end of the flight.
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Put it on the inside of the fuselage, I was reluctant to try this but after I got over the idea it worked out really well. Am running Hays 3 ounce clunk tanks on two profiles and getting the best engine runs I have ever had on a profile. Plumbed just like the instructions with the tank says, run muffler pressure to the top vent, drill out the middle vent and use it to fill, plug after filling. I bent and epoxied two 1/8 cross tubes behind the engine to get from one side of the fuselage to the other neatly.
Going to set up my Ringmaster the same way except with a 4 ounce tank.
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Bob,
I gave the idea of mounting the tank on the Ringmaster on the inboard side of the fuselage some thought awhile back but then forgot about doing that. Thanks for reminding me!
I did just that (inboard tank) on a throttle control profile a year or so ago because the pushrod to the throttle on this plane was on the outboard side. I didn't do much stunting with it. Loops and wing-overs were about it. It worked fine. I think, as long as a clunk set up is used, there shouldn't be any problems.
I'm not sure what you've done on your plane(s) with the double cross over tubes? On my throttle plane, I just drilled a hole in the fuse and ran the tubing through to the venturi.
Thanks for the help!
Joe
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On The RSM Ringmaster it is 3 1/2" from the leading edge to the head of the backplate bolts on a Fox 35. The RSM tank is 3" long. Tank is a GRW400U I hope this pic shows it well enough.
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Joe, maybe a couple pictures will help...