Fuel tank selector, fuel filters & pumps, fuel lines First is choosing fuel injection and electronic ignition, going with the SDS EM-5 described elsewhere. That choice meant a switchable feed from each tank to the filters and pumps and engine, then a return line flowing back to the same tank. Each strake has the standard outflow, plus a return line in the upper rear corner of the tank. I bought the recommended Andair “6-port” fuel selector and mounted the valve forward of the instrument panel (a cleaner look, more perceived cabin room). I chose to locate the fuel pumps and filters in the hell hole, increasing the distance between people and potential leaks. I also made covers for the hell hole, both a smaller one just aft of the main landing gear, and the larger one just forward. With tanks, fuel selector and pumps located, it was time to connect them. I chose to follow the sizing of the Andair selector, with -8 feed lines and -6 return lines. If I had it to do over I would have a -6 adapter on the Andair valve and make all lines with the -6. The flow would have been more than sufficient for the intended IO-360 and -6 would have been larger than the finger strainers at the tank exit. More radically, perhaps the tube bending and flaring and fittings could have been sidestepped with an automotive style flex fuel line. I went with stainless braided flex tube for my brake lines, and my next Cozy will explore flex braided fuel lines. Tanks. I have the plans fuel tanks, with a finger strainer exit. Fuel lines run underneath the aileron control rod, secured to the side wall with click bond studs and Ugolini-style hold down clips (a customized Adel clamp of sorts). I can remove the sidewall cover and access in-line fuel valves – both valves are secured open and were installed only for future convenience. I have a fuel return located in the upper corner of the tank; any bubbles from returning fuel should be far away from the sump. Fuel filters & pumps. Below are pictures of the fuel pumps and a “cap” made to hold the filters. This package fit neatly in the hell hole, where it can be put behind a barrier screen. Fuel from the selector comes to the rear, through a bulkhead fitting, across the main gear, through another bulkhead fitting, then into the first filter, the pumps, the second filter and then to a steel firewall fitting low on the firewall. The pressure regulator is mounted to the firewall to the left of the pumps + filters. It's hard to see, but the return fuel lines comes in from a steel bulkhead fitting on the lower left, through the regulator, then curves nicely to the bulkhead fitting. It crosses the main gear, then forward to another bulkhead fitting and onward to the fuel selector. Note that other builders have placed the pump and filters under the front seats - I don't know what's easier, but I've reserved that space for remote mounted avionics, whatever they turn out to be. (I chose to install cut off valves close to the tanks - the black hexagonal interruptions in the tubing.. They are wired open under the side panels, available only for an annual when I want to service the lines and spill as little as possible (!).) Materials, techniques & tools. The lines are made of VersaTube, a soft aluminum commonly used for this purpose. A 50 foot length each of -6 and -8 was sufficient. Burst strength varies with size (smaller is stronger), and all sizes are at least 10x the maximum pressure that can be generated by the fuel pumps. Experimenting with the tubing found that smaller sizes (-3) bend easily - I had a 8 foot length I used to template the bending of -6 and -8 tubing. I had _no_ luck with the standard "triple header tubing bender" sold everywhere - I got crushed spots, inconsistent bends and very difficult to get a finished bend out of the tool. I ended up using bending springs - the -6 bends well with an outer spring and the -8 requires both an inner and outer spring. The outer springs come as a set for a wide range of sizes and I found a -8 inner bending spring on eBay. (The inner bending spring for PVC will _not_ work on VersaTube.) My preferred technique came to be putting the tube in a spring and enclosing in a bending jib made from scrap plywood. I recommend you _not_ use the cheapest flaring set, but go up one grade to the $40-50 one. Below is a picture of the tools I used and the scrap I trimmed off when I decided to remake a part. The most common error was to make the tube just a bit too long, so I got to trim and remake the piece. The next most common was to flare before putting the nut and sleeve on the tube! Most everyone does the flares the same way. My only tip is to add a drop or two of cutting oil on the flare cone - I got super smooth faces. When it comes to fitting pieces, when I couldn't get the nut to to mate with the opposing threads it was where I had the one end secured and was fighting the other. Undo that first end and get alignment at the problem end, after which I was still able to reattach at the first. Fittings. I underestimated VersaTube, and assumed I would need a lot of 90 degree fittings to get good corners. Instead I was usually able to bend the tubing and get the job done without fittings. (This is preferred by SDS, where they want bends over fittings.) I hit my limit in the 180 degree bends of -8 used between fuel filters and fuel pumps. An inner spring plus an outer spring plus use of the bending jig got my parts aligned and fitted. Deciding how to piece the fuel lines then turns on design for future service. I have 3 pieces in each of the lines between fuel selector and tank, a count that made reasonable the install-remove cycle. 3 x 6 lines = 18 pieces, each with 2 ends. Add in the plumbing of filters and the pumps and you get practiced at making and appropriately flaring the tubing. Sealants. We pretty much all use Gasoila as the thread sealant for fuel lines. I also used a film of "EZ Turn" fuel lube on the faces of the fittings. A small tube of each is more than enough for the project.