ORIGINAL: gratechef
<span class=''Apple-style-span'' style=''font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13px; border-collapse: collapse; ''>I am installing a Fuel Dot & Switch on the side of my Big Stik 60 and have a question...
Adding a 3rd line for refueling in the nose of the fuel stopper requires that I then route the fuel line back through the fire wall to about the middle area of the fuselage where I am side mounting the dot & switch. Looks to me like I could simply tap into the back of the fuel tank which would be much closer, simpler and cleaner. It would also reduce clutter around the already crowded engine compartment. The only concern, of course, is the tank possibly leaking at the tap.
Has anyone ever successfully added the 3rd refueling line in this manner?</span>
I'm interested. I would NEVER do this on a plane, at least the first time, but if it worked there would be many interested.
For your experiment, put your engine on an engine stand. Make your hole in the tank and insert a bulkhead connector (available from DuBro and several other sources.) Use an appropriate O-ring inside for a seal, and add an appropriate seal on the outside to provide support and prevent aggravation of the stress riser. (The hole is a serious stress focusing point, making it easy for any vibration to cause a crack to propagate from the crack.) Mount the tank on the stand to feed the engine.
Run with a mildly unbalanced prop ('most any from the factory), and watch for leaks. If the system doesn't develop a leak after a few hours (let's say, 10 tanks) on the test stand... risk it in a plane. Fuelproof the area in the plane beforehand, in case of leaks. You'll want to monitor the location faithfully for many flights, in case of leak.
I don't expect the delicate tank to survive long after introduction of the stress riser, but I could be wrong.
Good luck,
Dave Olson