more unaflo tanks

[bob whitney]

I am starting a new post as I will probly ramble on a bit (who me)??
when working with tanks  one size dose not fit all.stunt and combat are diff animals than speed and racing. in speed Bill Wisnewski found that the vent tube needed to be at least 1/2 in from the fuse to get it out of the turbulence . he also found that with a flat sided speed tank by ending the vent tube near the top of the tank rather than right next to the engine feed tube that he could get it rich enough to get it on the pipe in the air on suction,
  in slow rat they use a big tank in the inside of the fuse feeding a smaller tank just behind the engine ,actually making it a chicken hopper tank the vent tube was placed in line with the needle valve  in the small tank , and they got a steady run from start to finish
  in slow combat most run the tank on a tank set up calling it a chicken hopper ,the vent tube comes out in about the middle front of the tank , I always run a piece of fuel tibing to a brass tube mounted to the top motor mount bolts and curved into the air flow,and I get a steady run  start to finish. one day one of the guys showed up with a slow combat ship with the same tank. . the second it was launched it would quit . we took my tube off of mine and put it on his and surprise it worked great. took it back off and again it would die on take off. some how the turbulence behind the engine was causing a problem.
  to me the two important things is the right location of the vent tube in the tank and keeping the vent tube opening out of any turbulence, which could be one of the problems when changing directrion in manuvers
  And just when u think u have it figured out along comes an ARF FLIGHT STREAK  that came with about 2 oz tank that would not run steady for a whole flight. we tried everything ,vent to the inside ,everything, .finally got mad and took the tank apart and could not find anything that should have made it act the way it did.  put a new 2 oz Brodak tank on it and it has been worked fine (still)

[Jim Mynes]

I use a battery. No matter where I position it I get the same run. I can put the wires in turbulence, out of turbulence, on or off the centerline of the motor, it just doesn't matter.
If I ran two batteries in series, would that be the equivalent of a chicken hopper?

[john e. holliday]

Nothing like pushing the limits.   My self I have had identical tanks constructed by me and even commercial tanks that would not run the same.  Actual experience was with Fox 1 ounce tanks for Shoestring racing.  My Sons plane was only getting 25 laps on his tank, with the speed of the plane and his Fox starting on one or two flip starts we got in the finals.  My plane would not restart and when it did it got almost 40 laps which was too much with the required fuel stops.  Changed tanks on the planes and a change in pit stop procedure the son of mine took first place.  Had Melvin on the battery and I was fueling and hitting the prop.  Nothing like knowing where the over flow is located.

Uni-flo tanks are something to get right almost most of the time.  I guess the plastic tanks are better as you don't have to take the tank apart to adjust the Uni-flo vent.