Future RV 9 Flyer
Active Member
I am about to close up the fuel tanks on my 9 but have questions about needing a return line if going with fuel injection.Is a return line needed with all fuel injection systems?thanks in advance !dh
Agreed with the two opinions above - some need it, some don't, and it will never again be as easy to put it in as it is right now.
I would suggest putting one in and capping it, you can always use it (or ignore it) later as you wish. Quite a few folks worry about foaming in the first bay where the fuel pickup is, from the fuel return line dumping in there. I put my return line AN fitting fairly high in the tank end plate, and routed an internal line through the first bay bulkhead so the return fuel dumps into the second bay, and gravity-flows along the bottom of the tank back to the fuel pickup, to minimize any chance of air bubbles or foaming making their way back to the fuel pickup.
I believe you will would need to install a "Duplex" fuel selector. It returns fuel back to the left tank when pulling from the left tank and same for the right tank. The valve is like a double valve. Here is a link showing a picture of the FS 20x20-3 duplex valve, http://www.andair.co.uk/system/index.html. Vans has one on the website. http://vansaircraft.com/cgi-bin/sto...9&browse=airframe&product=fuel-selector-valve. FS 20X7T is the single Andair valve and a FS 20x20-3 is the duplex. Both are listed on this page......The believe biggest obstacle when going this rout is the plumbing. Things can get mighty crowded under that fuel valve cover!
Simple question I could probably find if doing a search ....
Which FI system does not require a return line to the tank ... and what are the downside ?? I need to be thinking about a engine purchase ... 360 with a CS prop .. I have not fitted a return line fitting to the tanks .. Yes at this point in time I could pull the tank off the wings and install one .. but doing it in the section furthest away from the suction strainer will require a access hole cut in the rear. ... and I do not fancy all that extra piping in the cabin (RV6) ... Appreciate some thoughts on this ...