Uniflow tank

[Ed Neuzil]

After an 8-year layoff from the hobby, I am having a brain cramp.
I have a 4 oz. Brodak oval profile uniflow tank like the one pictured
which I want to use on a Twister I am currently building.
I have no documentation, and cannot remember which tube is the
uniflow vent and which is the fuel pickup which goes to the engine.
Thanks in advance.

[Tim Wescott]

Hopefully someone with one of those tanks will answer.

If not, it's most likely the outboard top tube is the fuel pickup, the inboard top tube is the vent, and the tube on the bottom is the overflow.

If you put some water or fuel into the tank with a syringe and hold it pointed side down, you should be able to draw liquid off with the vent tube, then get a bit more with the fuel pickup tube.

Or, if you know the part number, send an email to Brodak's and ask -- they're pretty responsive.

[Bill Little]

Tim got it right.

Generally, you cap off the overflow (single tube on bottom), and leave the uniflow either open or hook up muffler pressure to it.  I always use the uniflow vent to fuel the model.

BIG Bear
RNMM/AMM

[EddyR]

Top inside is uniflow . bottom vent, cap it for flying
Ed

[bill bischoff]

For future reference, it's easy to figure out for any tank. Put about 1/4 oz fuel in the tank. Turn the tank nose down and upside down, so that the fuel will be in the top front inboard corner. This is where the overflow tube will go in the tank. Whichever tube will actually suck the fuel out of the tank, that's the overflow. Now do the same thing, but hold the tank so the fuel will be in the outboard rear corner. The pickup tube will be the one that you can suck all the fuel out with. The uniflow vent will suck out some, but not all, of the fuel.

[Lynn Weedman]

If that tank is that old, Id'e take the back off of it and clean any rust or dried up fuel residue out of the inside then you will know what you have to work with is clean and you can note the position of the plumbing. I always do that to an old tank saves you a lot of headaches on the flying circle....


Lynn Weedman

[DanielGelinas]

Funny....
I asked the same question to Brodaks for there 2 1/2 oz tank two days ago. They told me the upper OUTBOARD tube was the uniflow tube which is really not what I was expecting!!!
-Dan

[ray copeland]

Okay, the tank i received from Brodak's last week included a chart of their most popular tanks with descriptions. On the tank in question, according to the chart , the tubes are as follows:  facing the front of the tank , the bottom tube is the overflow. The tube on the top right is the uniflow, the tube on the top left is the pickup.  This makes sense and is the only way i have seen tanks of this type set up.

[Dan McEntee]

  Or you could just fill it. If it's a 2 ounce tank, it will only take about half that before fuel starts to come out of the uniflow. Going the other way, it should fill up for the full amount or very near it if done correctly.
   Type at you later,
   Dan McEntee