Deep into the build of the avionics harnesses, I suddenly had a revelation ? if we continued on the track I was going, it was going to be more and more difficult to remove the avionics stack rack structure. Oh, it will come out, but doing so will involve far more disconnection than I?d want to do more than occasionally. The only problem with this was that the fuel valve (and the tank to valve plumbing) is located sort-of underneath the stack. In addition, the EFII Boost Pump is going to go just forward of the stack, in the ?tunnel? between the rudder pedals. Figuring all this out meant it was time to put down the wiring tools for a few days and get out the plumbing stuff ? it was time to install some fuel lines!
Once again, the simplicity of the RV-3 shines ? the two lines from the tanks would only need a few bends, the line from the valve to the filter would be similarly easy ? the only real creativity was going to be required in mounting the pump and filter. In the interest of stiffening up the two triangular ribs that support the center of the firewall even more, I decided that a bracket for the pump that joins the top would work well and allow easy maintenance. The new EFII pump has numerous drilled and tapped mounting holes, so finding a set I liked was simple. Figuring how far back to place it from the firewall was a matter of building up a temporary fuel line (temporary because I am not sure just where I want the firewall penetration to be yet ? never drill until you have to!) and seeing what clearance I needed for the appropriate radius. I mounted the pump off-center to allow room for the clean-able inline filter on the other side ? I built a bracket for that with a piece of large elevator pushrod tubing cut in half to create a saddle ? it will be held in place with a hose clamp (Tie-wraps for now). The ?tunnel? area is just a little too short to mount the filter and pump in line with sufficient room for a pipe to join them, so the fuel flow has to ?wrap around? to work. (If I?d gone with Robert?s shorter, disposable filter, there would probably be room, but I like this pretty blue anodized thing with a cleanable screen?.)
Making the tank-to-valve lines was fairly straightforward. I used a piece of solid house wire that would hold its shape to make a template ? put the bends where I wanted them, and the angles just right. It was simple to then bend a piece of tubing to the same shape and dimensions. The fuel valve is symmetrical in the fuselage, so I didn?t even have to make a form for the opposite side, just had to do the origami in my head to make a mirror image ? both fit perfectly! Support Adel clamps will be installed later on. (BTW, a long coil of fuel line is pretty cheap from ACS ? nice to have on hand to keep you from cheating and not starting over when you mess one up. I?m on my first coil of tubing and finishing the third fuel system I have plumbed.) Still to go will be vent lines, but they won?t be blocked by continued wiring work, so we can do them later.
House wire makes a good forming template:
I like to make nice straight runs and square corners when I can:
I love the simplicity of the RV-3 ? very few lines are required!
(Note that the avionics stack in these photos is sitting over in the right leg well ? I left enough harness slack to move it around for just this kind of work!)
Paul
Once again, the simplicity of the RV-3 shines ? the two lines from the tanks would only need a few bends, the line from the valve to the filter would be similarly easy ? the only real creativity was going to be required in mounting the pump and filter. In the interest of stiffening up the two triangular ribs that support the center of the firewall even more, I decided that a bracket for the pump that joins the top would work well and allow easy maintenance. The new EFII pump has numerous drilled and tapped mounting holes, so finding a set I liked was simple. Figuring how far back to place it from the firewall was a matter of building up a temporary fuel line (temporary because I am not sure just where I want the firewall penetration to be yet ? never drill until you have to!) and seeing what clearance I needed for the appropriate radius. I mounted the pump off-center to allow room for the clean-able inline filter on the other side ? I built a bracket for that with a piece of large elevator pushrod tubing cut in half to create a saddle ? it will be held in place with a hose clamp (Tie-wraps for now). The ?tunnel? area is just a little too short to mount the filter and pump in line with sufficient room for a pipe to join them, so the fuel flow has to ?wrap around? to work. (If I?d gone with Robert?s shorter, disposable filter, there would probably be room, but I like this pretty blue anodized thing with a cleanable screen?.)
Making the tank-to-valve lines was fairly straightforward. I used a piece of solid house wire that would hold its shape to make a template ? put the bends where I wanted them, and the angles just right. It was simple to then bend a piece of tubing to the same shape and dimensions. The fuel valve is symmetrical in the fuselage, so I didn?t even have to make a form for the opposite side, just had to do the origami in my head to make a mirror image ? both fit perfectly! Support Adel clamps will be installed later on. (BTW, a long coil of fuel line is pretty cheap from ACS ? nice to have on hand to keep you from cheating and not starting over when you mess one up. I?m on my first coil of tubing and finishing the third fuel system I have plumbed.) Still to go will be vent lines, but they won?t be blocked by continued wiring work, so we can do them later.
House wire makes a good forming template:
I like to make nice straight runs and square corners when I can:
I love the simplicity of the RV-3 ? very few lines are required!
(Note that the avionics stack in these photos is sitting over in the right leg well ? I left enough harness slack to move it around for just this kind of work!)
Paul
