[loopfuzz]

I'm looking to convert one of my tanks on my -4 to a inverted fuel tank. So using the flop tube that vans sells, I'm just wondering what the procedure would be for converting a already existing tank.

Any tips on doing this? Has anyone converted a normal tank to a inverted tank before?

Thanks!

 

[scsmith]

Many have done this -

When you get a quickbuild kit and want a flop tube, you have to do this.

I took the right tank off, cut a hole in the rear face of the tank in the second rib bay to install the tank float sensor there. I made a doubler ring with nut plates on it, split it so it could be fit into the hole, and riveted it on with lots of proseal.

Then, I went inside the tank through the normal end hole and installed the deflectors to keep the flop tube from getting hung up on the stiffeners, and installed the flop tube itself. Then, I closed up the tank.

 

[mototopo]

Do I need a doubler ring?

In my not-QB tank I installed the fuel sender in the second bay but without a doubler, I just riveted the nut plates on the tank baffle. There is no mention for a doubler in the instruction so I gone straight with this solution. Do a doubler ring is necessary?? (Hope not!!!)

 

[scsmith]

doubler not necessary

I don't think a doubler is truely necessary. It's just easier to install the nutplates on a separate part and then install it in the tank if the tank is already finished. If you are building a tank from scratch, a doubler may still be a good idea to prevent any flexing of the baffle, but probably not necessary.