Hi All:

    I was in the shop converting some metal tanks to uniflow when I had an idea.  Why not have all of the tubes placed in the front of the tank? All of my tanks have the pickup at the rearmost corner of the tank with one being 5" from the front of the tank. Add a couple of more inches of travel to the nva and one has a long path for the fuel to travel!

   I thought that if I place the pickup in the front of the tank, this would make the fuel travel much less. Of course I would kick the front corner of te tank outboard or make the tank wider at the front than the back to get the fuel to drain to the front.  The uniflow vent could also be in the fron! I have seen tanks setup for racing with the tubes in the front of the tank.  Would this be a good idea for a stunt tank?

                                                                                              Frank

Yes, and you can buy them that way. The Uniflow inlet and overflow are then remotely mounted and hooked up with a bit of fuel hose. This works just fine, but you do want the remote Uniflow tube to be above the top of the tank.

Sometimes there is a question about which tube is which, but otherwise, it's a good plan if you want to slide the tank in/out through the engine bay. If you like to remove your engine to shim the tank up/down to adjust engine run during insides/outsides.  

Kinda depends on how much your engine of choice vibrates. If you have a smooth running engine, dropping the tank out the bottom (top if an upright engine) is less hassle, but the remote exterior tubes are still a good thing. Different strokes.   Steve  

      Hi Steve et. al.:

      Yes, I am thinking of having the plumbing on the inside of the tank near the front wall.  What would be different than having the plumbing near the bck wall, rear of tank? We have seen tanks set up for racing set up this way for years.

      I remember that years ago I read that the reason our stunt planes go ito a 4-2-4 mode was that the engine leaned out as it tried to pull the fuel vertically from the tank.  It was also suggested that if one was not getting a good 4-2-4 break, he should move the tank back farther from the engine to make the engine become more lean as it went into a vertical position.

     

                                                                                  Be well,

                                                                                  Frank

                                                                       

       

   

 
      Yes, I am thinking of having the plumbing on the inside of the tank near the front wall.  What would be different than having the plumbing near the bck wall, rear of tank? We have seen tanks set up for racing set up this way for years.
              
                                                    

Hi Frank,

To my mind, the thing with racers is that they don't pull up into vertical climbs!  I'm thinking about where you've got considerably less than a full tank and establish a vertical climb - even with centrifugal force still pushing fuel to the outside edge, you may still find your engine sucking air suddenly.  Sure it'll run a little while due to the fuel already in the line, but that might be just enough to get you overhead for the start of the o'head 8s....

Steve

Frank, there are no stupid questions. 

Front feed tanks work perfectly well for vintage combat models, so there is really no reason why it can't be made to work for stunt models.

The combat environment is more demanding than aerobatics.

The ones I've seen are for use by 15 - 19 size diesels on suction. So there is no muffler pressure to "help" out. From memory the front outside corner was constructed at about 75degrees. Fuel pick up was located in the centre and the uniflow about the centre of the tank. A small baffle about 1/2 to 3/4" out took care of the more violent maneuvers.

Drawing attached

Greg