Fuel system testing

[RVG8tor]

Air Flow Performance manual mentions getting a cheap auto fuel pump and filter to pump some fuel from the tank before hooking up to the primary filter and pump. They mention composite planes which I guess can have tiny contaminant in the tanks.

Did you guys do something similar with RV tanks. Seems the way the tanks are built leave them pretty clean. Mine are QB, I have only inspected with a snake camera and did not find any issues but I could not see in every bay of the tank. I am nearing the time to do the shake down on the fuel system before the first engine start, I certainly want to make sure any crud is out of there before pumping it to the engine.

If you did a right up or log of what you did I and I am sure others would be interested.

Here is what I am thinking:

1. Use some pump filter set up to pump 5-8 gal from the tank out the tank pickup before the fuel selector and filter. Repeat until the fuel flow is clean clean (Dynon EFIS calibration still needs to be done, can this wait until first real fill up?) What is they typical unusable fuel?
2. Hook back to aircraft system, and pump fuel but tap into system before the engine, test flow of primary fuel pump here. After this inspect filer (maybe sue cheap filter for this as well) or just check the primary filter.
3. Hook up to engine and do other flow tests before engine start.

Does this sound about right, I need to cobble together some lines an stuff so researching what I will need. Taping into the fuel system inside the cockpit is a bit tough so that is why I am thinking the first test for major debris should be done at the tank outlet.

Thanks

[Rupester]

I used a very similar procedure ... except I also sloshed the tanks with 2 to 3 gals each by rocking the wings up and down, then drained that fuel out the sump ports thru a fine mesh filter and re-used it. I got zero debris. When all the lines and the FI pump/filter rig were hooked up, I ran the boost pump and pumped into a graduated container before the engine-driven f. pump, and timed with a stop watch. This was to assure I had no restrictions in the flow path on either side. IIRC, I got 15gpm + or - 0.5 GPM on each side.

[Norman CYYJ]

That is an awful amount of fuel flow for your pump or is it a miss print?

900 gallons per hour???

[Mark Browning]

It was a few years ago when I built my wing tanks ( slow build )
I took a real simple appraoch to my tank testing.

The leak check:- I tried the balloon test but had inconclusive results So then I thought why not fill her up with gas 100LL and leave the tank on the work bench for a couple of days ? I checked the soft tissue paper the tank was sat on for leaks. After a few days i had no leaks

Testing the tank sender with the steam gauge proved that worked, so all a needed to do was check for flow & debris.

After hooking up the facit fuel pump and checked the flow with the pump running... no problems there. I don’t have my flow results now; but it was way more than the Lycoming could ever use.
I then drained the tank and used a fine funnel filter to check for crud;
Once the tank got down to 1/4 full we sloshed the rest of the gas around before continuing to drain absolutely nothing came out ! Simple as that

[Wayne Gillispie]

I cleaned tanks before installing. Filled one tank, calibrated fuel level sender. Flow tested 42 gph at fuel servo inlet connection with 15' rubber fuel hose into 5 gal jug. That is with red cube in the tunnel, so plenty of flow for a 540. Refilled that tank and pumped it all to opposite tank through 15' hose with boost pump. While doing that, calibrated GRT fuel flow and other fuel level sender. Never had to adjust anything afterwards and within .5 gal at each fill.

[gasman]

Originally Posted by Wayne Gillispie

I cleaned tanks before installing. Filled one tank, calibrated fuel level sender. Flow tested 42 gph at fuel servo inlet connection with 15' rubber fuel hose into 5 gal jug. That is with red cube in the tunnel, so plenty of flow for a 540. Refilled that tank and pumped it all to opposite tank through 15' hose with boost pump. While doing that, calibrated GRT fuel flow and other fuel level sender. Never had to adjust anything afterwards and within .5 gal at each fill.

I can get that using my dip stick...............