homemade dual-feed fuel tank for bench running

roddie Mon Apr 23, 2018 7:47 am

I made this from a plastic 35mm film canister, a pair of the lg. size Perfect-brand lead-out eyelets (for fittings) and some silicone fuel tubing. I also used some thin rubber for seals, where the eyelets and mounting-screw go through the bottom. The cap has a small vent-hole drilled through. These film canisters are flat on the bottom for a better seal.. and "translucent" for viewing the fuel-level.

homemade dual-feed fuel tank for bench running Dsc05710

homemade dual-feed fuel tank for bench running Dsc05711

I used a slightly smaller drill-bit to make the holes for the fittings. This helps to create a better seal against leakage. The fittings (lead-out eyelets) receive thin-rubber seals.. and are then installed through the inside-bottom of the canister using an awl. The awl also applies pressure for when installing the fuel-line(s) which should slide all the way on.. and contact the bottom of the canister for additional sealing on the outside.

The first version was an opaque (black) film canister that had a "ridge" on the bottom, preventing a good seal.. and used small-size lead-out eyelets which would not secure my small-size Dubro fuel-line once the line was wet with fuel/oil. The larger fittings on this 2nd version hold tighter.. and will also flow more fuel for running a larger-displacement engine.

It takes a little effort.. but it worked really well.. and didn't cost me a cent.

Surfer_kris Mon Apr 23, 2018 11:46 am

Rather than drilling a hole, one can use a heated wire (or the back-end of a drill) and melt a hole through the plastic. This way you get a very smooth surface of the whole, which will seal directly onto a silicon tube pulled through it. The will be a small piece of fuel tubing inside the tank and if you place a suitable brass tube there, it will act as a stop that prevents the tubing from being accidentally pulled out. This method will work well on the black containers as well, as the sealing is inside the hole rather than against the surface.

roddie Mon Apr 23, 2018 6:23 pm

I like that approach Krister! Thumbs Up

It certainly simplifies the sealing-process of the line(s) coming out of the tank.

NEW222 Mon Apr 23, 2018 8:17 pm

Great job on the tank. A very simple yet, very easy approach to feeding two engines. Will you be trying something like this in a plane, or did you just build it for bench running?

roddie Thu Apr 26, 2018 10:06 am

NEW222 wrote:Great job on the tank. A very simple yet, very easy approach to feeding two engines. Will you be trying something like this in a plane, or did you just build it for bench running?

Hi Chancey, It was built for bench-running only.. and merely as a convenience. I think it would be complicated to have a single tank feeding twin-engines on a model airplane. My engines will be relying on suction alone, to pull fuel.

My control-line P38 will have separate wedge-style fuel-tanks for each engine.. and the fuel-lines will be very short. I just hope there's enough fuel-capacity to get the airplane off the ground before the fuel-level drops below the feed-tubes in the tanks. The tanks are 7.4cc's.. but will only feed "static" around 3.5cc's before the engines start to suck air. I'll need to start the inboard engine first.. and "top-off" its tank last.. before takeoff.