Something "Different"....

Now that's MY kind of set-up! Yep, secure the line so it stays put. Also, which you probably have already done...double check the C.G. !!!

Aerodynamics? Heck, they're highly over-rated anyway !!!!

Also, be sure to prime the fuel line so it's full before starting !!

Alrighty then!

I just wanted flight times more than 2 minutes long. Will it stabilize the fuel draw? Before it sloshed around the pickup and ran very rough in the air. I wonder if the tank will be kept full, or at pickup tube level.

Kim wrote:Also, be sure to prime the fuel line so it's full before starting !!

Will do - I always have trouble with air bubbles.

It will keep it full which will definitely help. When it tries to slosh it around the pickup will still be sunk in fuel. Test it out first to check for bugs. The only thing I can see happening is the line coming off of the tank.

Quick thought. Can you route a tube from the metal fill tube inside to the fuel nipple? And then connect a line to the same intake tube on the outside to the external tank? Doing this would allow you to connect directly to the external tank and not even have to worry about filling the integral tank.

I realize it may be a bit difficult to manuver the tube, but with proper length and diameter it may work.

GENIUS ALERT!
Godsey, You may be on to something.
Never heard of this being done, but with some silicon
tubing and a couple of springs it sure looks possible.
I hate seeing holes drilled in perfectly good tanks to achieve the same thing.

Clever thinking, I'd say.
Bob

I suggested the same thing a month ago. After seeing Kim's Golden bee engine running off an external tank. Nobody called me a genius..........

Edit: My mistake it wasn't my idea it was Matt's another young genius!

It was in reference to pee wee backplates. He posted the idea and I clarified. I do think it would work and the mod would be totally doable and it wouldn't make a difference if you nipped the vent tube in the inside of the tank. Just do it on the fill tube so you can still fill the tank should you ever want to use it in a regular application again.

The vent tubes on all but one of my BWs end only a few millimeters from the inside of the tank so there is no way to attach a tube. On one of them, the bottom tube is short, about a quarter inch from the tank side. that might be enough room.
I wouldn't bother with springs. I found the fuel will follow the first spring to its end and not continue up the next one. Screwing them together solves that to some extent, but it ends up being sort of a kludge. They might vibrate apart. I'd just leave the lines empty.

RknRusty wrote:The vent tubes on all but one of my BWs end only a few millimeters from the inside of the tank so there is no way to attach a tube. On one of them, the bottom tube is short, about a quarter inch from the tank side. that might be enough room.
I wouldn't bother with springs. I found the fuel will follow the first spring to its end and not continue up the next one. Screwing them together solves that to some extent, but it ends up being sort of a kludge. They might vibrate apart. I'd just leave the lines empty.

Just nip off some of the vent tube.

I think since they are still plentiful, and the aluminum 8cc tanks are back, I'd buy a new tank tank and bore a hole in it. Or the old one if you're not too sentimental.

RknRusty wrote:I think since they are still plentiful, and the aluminum 8cc tanks are back, I'd buy a new tank tank and bore a hole in it. Or the old one if you're not too sentimental.

Or nip off some of the vent line..... Beats drilling a hole in the tank.

...or save the tank and swap it out with a common Sure Start backplate.

Drilling a hole into tank for a fuel line is pretty common, I have a RR-1 tank that someone did that to.

All good stuff guys, thanks.

As discussed in my build log, the engine is not removable from the plane. So It would be impossible to do anything else.

I also have a Perfect 3/4oz metal tank.

I'm being a bit thick Matt but I'm having trouble seeing where your fuel tube is connecting to the engine.
Is that cap head bolt on the top tank vent 'sealing' the tank somehow?
If yes then thats probably where your bubbles are coming from, threaded bolts don't make very good fuel line
plugs use a proper fuel dot, a small dowl or anything solid.
Another place to look is your vent tube into the wing tank, is it at the top of the tank? if so is it touching the roof
of the tank? a big no no, is it at the rear of the tank near the pick up? another source of air into the fuel
line.
Finally is the wing tank above c of g?

looks fine Matt. With the setup you have pictured, the only thing I would maybe add would be a piece of fuel tubing to the wing tank vent and run it down and capture it in the rubber bands on the front right side there,,dont pinch it off obviously. just stick it in there to be held. You might get a stovepipe effect from the airflow across it and it might pull fuel out of the vent on a full tank and it sloshing around,,without the tubing.

Maybe fill the wing tank to about 1/2 to 3/4 and try that. Prime that line like Kim mentioned. If you get a rough run once it is airborn, you might pull the inline filter and try it without. Although they do filter fuel and it is a good idea, they do cause a fuel flow restriction on a small motor.

A piece of closed cell foam under your wing tank might not hurt either, for vibration insulation.

Good luck.

I might crank it up today - I have about 6 ounces of fuel left.

The ID of the tubing was too big to fit on the engine tank vent, so I got a small piece of .020 pickup tubing for an adapter.

The 1oz tanks is set up like most. Vent tube is in the little bubble on the top.