multiple fuel tank question and air bubbles
08-24-2008 | 09:46 PM
#1
Thread Starter
multiple fuel tank question and air bubbles
question
Due to the shape of my fuel tanks its hard to get the clunks to fall into place. Ie tank upside down clunk goes to the bottom (top)
Tanks A and B the funny shaped tanks are T'ed into C. Then C feeds the UAT. If tanks A and B feed air to C during inverted flight then flying right side up A and B resuply C with fuel. Will the air bubble, big or small, be displaced with fuel. Or will the bubble stay there and grow whenever more air is introduced.
David
Due to the shape of my fuel tanks its hard to get the clunks to fall into place. Ie tank upside down clunk goes to the bottom (top)
Tanks A and B the funny shaped tanks are T'ed into C. Then C feeds the UAT. If tanks A and B feed air to C during inverted flight then flying right side up A and B resuply C with fuel. Will the air bubble, big or small, be displaced with fuel. Or will the bubble stay there and grow whenever more air is introduced.
David
08-24-2008 | 11:08 PM
#3
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From: Mt. Vernon, IL
RE: multiple fuel tank question and air bubbles
But once tanks A and B start flowing fuel again air bubble and fuel level in C stays the same. Still will be able to use all the fuel unless you fly inverted till tank C is empty.
08-25-2008 | 09:16 AM
#4
My Feedback: (5)
RE: multiple fuel tank question and air bubbles
Just to add to the comments above, tank C will only get air from tanks A & B if they are almost empty and thus the clunks don't reach down (up) far enough when you are inverted. If A & B are larger than C and contain most of the fuel and you do your extended inverted flying during the first part of the flight, you shouldn't get much or any air in C. You can monitor it during the first couple of flights. Still, I wouldn't spend an extended period of time inverted during the latter portion of the flight or you'll suck 7-9 oz of air a minute into C some of which may make it's way to the UAT if your clunk in C doesn't always remain in the fuel.
I had similar problem with the clunks in my main tanks. The hole in the tank for the stopper was on the top face near the back of the tank. Needless to say, this would be fine for upright flight but totally unacceptable for inverted flight. I solved the problem by bending a long piece of 5/32 brass tubing using a Dubro bender. [link=http://www.shopatron.com/product/part_number=786/101.0]http://www.shopatron.com/product/part_number=786/101.0[/link]. The tube runs vertically down through the stopper, takes a 90 degree bend, runs forward to the front of the tank, then bends 180 degrees to run rearward for an inch. This places the end of the brass tubing where it normally would be if the stopper had been at the front of the tank and the clunk reaches to the top/bottom.
Regards,
Jim
I had similar problem with the clunks in my main tanks. The hole in the tank for the stopper was on the top face near the back of the tank. Needless to say, this would be fine for upright flight but totally unacceptable for inverted flight. I solved the problem by bending a long piece of 5/32 brass tubing using a Dubro bender. [link=http://www.shopatron.com/product/part_number=786/101.0]http://www.shopatron.com/product/part_number=786/101.0[/link]. The tube runs vertically down through the stopper, takes a 90 degree bend, runs forward to the front of the tank, then bends 180 degrees to run rearward for an inch. This places the end of the brass tubing where it normally would be if the stopper had been at the front of the tank and the clunk reaches to the top/bottom.
Regards,
Jim
