I need some help planning a fuel return for my qb wings

[danlh]

I would like to install a fuel return line in my quick build wings and was wondering if anyone has any advice on the installation.
Pictures would be helpful. Also what parts would I need at the fuel tank. Best location to drill the hole? Any other advice?
Thanks!
Dan

 

[recapen]

I installed a -6 return line above and behind the fuel guage panel and ran the return line into the second fuel tank bay for mix cooling during a hotstart. I used standard AN-6 fittings and a passthrough like the ones used for the rudder cables through the bulkheads to support the -6 line into the second bay...

 

[planenutz]

Similar to Ralph, I ran the return -6 aluminium tube from the right side of the firewall, vertically down the side then aft. I used a bulkhead fitting in the side skin penetration and in the tank I placed the bulkhead fitting aft of the forward tank/fuse attachment and forward of the tank cover-plate. The connection between the fuselage and the tank was made in a "u-shape" so that there was as little stress on the tube as possible - and for safety in an accident.

This photo shows the two fittings in the side of the fuselage - one for the fuel vent and the other for the fuel return line:


The last photo shows some of the path the return line follows... this is essentially following the RV-6 Fuel Tank Vent Line, as per the plans. The two tubes are clamped together.

Hope this helps.

 

[TS Flightlines]

Similar to Ralph, I ran the return -6 aluminium tube from the right side of the firewall, vertically down the side then aft. I used a bulkhead fitting in the side skin penetration and in the tank I placed the bulkhead fitting aft of the forward tank/fuse attachment and forward of the tank cover-plate. The connection between the fuselage and the tank was made un a "u-shape" so that there was as little stress on the tube as possible and for safety in an accident.

This photo shows the two fittings in the side of the fuselage - one for the fuel vent and the other for the fuel return line:
View attachment 94422

I have photos of the inside somewhere... I'll try and find them.

Dan---check your tank end ribs, but since you said QB wings, they may or may not have the end ribs set up for an upper VA141 tank bung. Never the less----about in the spot like you see in this pic.
Tom

 

[Larrysc]

I understood the return line to the tank should connect at least 3” from the supply line. Does anyone have it closer and if so have you had any issues with bubbles entering the supply line?

 

[dmattmul]

I would like to install a fuel return line in my quick build wings and was wondering if anyone has any advice on the installation.
Pictures would be helpful. Also what parts would I need at the fuel tank. Best location to drill the hole? Any other advice?
Thanks!
Dan

The 14 is the same wing, (Just shorter) why not locate it where Vans recommends? Has worked perfect on mine.

 

[Larrysc]

The 14 is the same wing, (Just shorter) why not locate it where Vans recommends? Has worked perfect on mine.

View attachment 94469

Thank you! My challenge is that I purchased this project partially built and the return line is already installed so I need to determine if I need to cut a new hole. It will be more difficult as the wing is complete and sealed up. I wanted to learn if anyone has placed it closer than 3” to the supply connection and if it caused any issues.

 

[dmattmul]

Thank you! My challenge is that I purchased this project partially built and the return line is already installed so I need to determine if I need to cut a new hole. It will be more difficult as the wing is complete and sealed up. I wanted to learn if anyone has placed it closer than 3” to the supply connection and if it caused any issues.

I was responding to the OP's question. If you have a new question (seems you do as your new question was anything but clear), post a picture of how your previous builder did this. Is it like 1 inch away? That will not work. Next to it 2 in probably a non-starter. Not sure how someone could place this less than 3" from the supply but always a possibility to screw this up. Seems the first builder might have not understood what he was designing and building, DANGER WILL ROBINSON........Please don't blame your EFI system when it does not work correctly.

I'm fairly certain nobody will tell you it's ok to deviate from specifications, if they do maybe they never performed a 60-degree base to final with min fuel while drawing on the wing high tank or hundreds of other unique fuel supply orientations. My point is most likely nobody has explored all points of the fuel supply envelope.

 

[lr172]

Thank you! My challenge is that I purchased this project partially built and the return line is already installed so I need to determine if I need to cut a new hole. It will be more difficult as the wing is complete and sealed up. I wanted to learn if anyone has placed it closer than 3” to the supply connection and if it caused any issues.

Is this on a 10? Is the fitting above the supply or next to it on the bottom?

 

[danlh]

Thanks to everyone that replied with suggestions and pictures. The upper forward area as in Tom’s and dmattmul’s posts may work. I was looking at Glenn family build. He is dealing with an rv10 qb also and was concerned with the clearance from the wing spar carry-thru in that location. He placed an externally mounted bung just forward of the vent line.
I’ll take a look at both locations.
Dan