Magnum uniflow tank question

I would like to find out how the plumbing is routed INSIDE the tank. It looks like something I could modify to use on a current project if I can figure out the inside plumbing. Anyone have a drawing or sketch of it?

If you're refering to the Magnum style available from Brodak, it is the same as any other uniflow tank. Vent goes to the inside front top, pickup to the outside aft end in the center of the wedge (they use a bologna slice at the end of the pickup tube), and the uniflow vent is next to the pick up but ends about 1/8 to 1/4" fwd of the pickup.

The only difference really is the way the tubes exit the tank.

FWIW

In case you don,t know , you must plug the overflow , or vent tube , or the uniflow will not work properly.
If you leave the vent unplugged it becomes a regular tank , usually
running faster as the flight progresses.
So, if you build a uniflow tank you have potentialy two types of tanks.
It,s a win win situation in my book;highly reccommended.

LAST EDITED ON Dec-08-04 AT 09:23 PM (CST)
 
On the Magnum tank Brodak sells are two outlets that are right together and come from the underside of the tank. They make an out and upward turn and look like they would run up the side of the plane on the outside of the fuselage. It appears one would be a fill and the other an overflow - probably for use as a non uniflow tank. What I want to do is to modify a tank I have to use the idea of the tubes coming out the bottom of the tank as the Magnum does (because of a clearance problem) but keep the pipes inside the fuselage except for two short pieces of tubing that come out and do an immediate bend with the open ends into the wind. I want to use it as a non uniflow tank. The question is how to run the tubing inside so it does not syphon the fuel out and still give air pressure to the tank equally in upright and inverted flight. I am looking for standard venting with both fill and overflow tubes coming out the bottom of the tank

Bill

The fill line would have to end much lower than the overflow line which would end at the top of the tank. You could end the fill line anywhere from just inside the tank to maybe 3/4 of the way through it. What you want to avoid is having the fill line tall enough that fuel will splash in to the overflow line. I would worry that the line is only supported where it passes through the tank allowing the solder joint to flex until it breaks.

If the outside of the fill line ends below the top of the tank you will have a problem with the fuel siphoning out until you plug the tube. That is one reason why the magnum tank has the lines curving up outside the plane.

LAST EDITED ON Dec-09-04 AT 07:04 AM (CST)
 
>I would like to find out how the plumbing is routed INSIDE
>the tank. It looks like something I could modify to use on a
>current project if I can figure out the inside plumbing.
>Anyone have a drawing or sketch of it?
>

No doubt someone will differ with me, but here's my sketch;

Kinda ugly art work, eh??

The B vent (bottom) enters to Bottom of the tank and must exit in the inside of the flight circle above the fuel level,

The T (top) vent goes to the top of the tank and can be at any vertcal position that fits the plane. It must also be inside the circle with respect to the fuel.

This is the "traditional stunt venting". It will not spill fuel under any condition, but the engine will run a little leaner as fuel is burned. Plug the UNI vent to run this way.

The UNI vent is located very near the fuel pickup in the extreme rear corner of he tank. It terminates in the upper, top, inside corner of the tank. This is necessary to avoid spilling fuel on the ground. In the UNI mode, the T & B vents are connected with flex hose after fueling.

Basic stuff, as far as I know. I also think tank makers should just make tanks with NO VENTS at all. I just have to plug the holes when I move 'em all.