I have been trying a couple ideas this winter for extra fuel. I dont want to stand on the tire and hoist up 6 gallon cans.
My friend in the fish guiding business uses these Nauta flex bag fuel tanks in his boat. They come in various sizes but the one I used was 13 gallons. I put a hydraulic coupler on the out fitting, that connects to a 12 v fuel pump
IMG_3103.jpg
I had some Tygon gasoline hose, that I hooked to the discharge on the pump, and on the other end I put my spare Carbon Cub fuel cap. The pump is a 12 v unit that I got on amazon that is rated at 100 gph flow. I plug it into the cigar lighter accy socket. The male plug in has a built in switch, I was trying to eliminate a sparkIMG_3099.jpg
when you land and want some fuel, you take the tank cap end up on the wing and install it (I took out the blue gasket to let the tank vent), plug in the 12 v plug, open the tank valve and pump away. It takes about 15 mins to pump out 13 gallon, so the pump is quite a bit less than 100 gph
I have used it all winter, and it works ok, but I have some concerns:
I hate to fill it in the plane, so I have been laying it on the ground. it kind of self inflates with the inflowing gas. Then its a struggle to lift up 13 gals of gas sack and get it in the baggage. I lash it down on the corners. I have filled it in place a couple times in the plane, but worry about static. Also the static as the gas is pumped from sack in baggage to wing.
also a fairly good size explosive sack of gas inside the cockpit in a crash
A question for the engineers in Yakima, could the pump discharge be Teed into the under fuselage drain line coming from the right wing to the drain? The pump could be operated in flight to fill the main tanks back up. I have studied the tank piping schematic from the maintainance manual, and both tanks drain to the back drain. If the pump is run at altitude will that pressurize the lines, or not since it is going back up into the tanks that are vented. What about the gascolator carburator? they were designed for gravity flow. Shut one tank off and fill the other? I hate to mess with a fuel system that works well, and sometimes there are things that happen that are unforseen
the system is great in that you take it out when you dont need it, and you have another 13 gals on board
when I took the cub from Maine to FL and return this winter, it came in handy a couple times, but usually when you stop you are at an airport with fuel. It works but is not ideal.
Been looking at these aluminum fuel cells with a built in transfer pump as well
91018661_L_1578e242-5373-4339-88f5-45a5627615c3.jpg
they have some crashworthiness built in, but are heavy Randy! 16 lbs, and are fairly spendy
I like the idea of being able to remove the weight when you dont need the extra fuel. I am also sure cubcrafters could do a much more elegant solution than mine. A really light CF tank that goes in baggage and plugs in
Fireawy
jim