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"Fuselage to tank" fuel line lengths?
Hello,
I am currently installing the fuel lines, or at least trying to, in my 9A. In a tail dragger it will be a lot easier, but in an ?A? it is hardly impossible to run the fuel lines as per the drawings, in one piece. The vent lines were easy, especially because I have not riveted the firewall yet, to have good access to the forward fuselage for installing fuel lines, fuel valve, FI-boost pump, etc. I think it is impossible to install the fuel lines in one piece without getting kinks or nicks in them, while you are trying to push the tube around all the corners (behind the gear mount?). Because I am also installing return lines to the tanks (FI) and use a double stack Andair valve, these fuel lines are a real pain. I have decided to run the fuel lines in front of the gear mount (they get covered by the CAD-interior anyway) and make the return lines in two pieces, connected with a straight coupling, to make things work at all. Now to the question: Does anybody know how much the fuel and vent lines have to stick out of the fuselage, to be able to connect directly to the couplings in the tank? I can't find it on the drawings, or in the manual anywhere! I have not planned to put the wings on for a long time yet, but I do want to finish the flares on the fuel and vent lines now, because ones the tubes are completely installed, the flaring tool I use, will no longer fit and it will be impossible to make the flares, with the nuts and sleeves on. Looking forward to the answers of the experts! Regards, PilotTonny. |
here is how I ran my fuel lines in a 7A
Running the fuel lines from the fuel selector to the wing roots is a pain in the A models because of the landing gear weldments. One method that worked for me was to use a piece of clear nylon hose with an inside diameter slightly larger than the outside diameter of the aluminum tubing. I put a few drops of tool oil in the nylon tubing and ran it from the hole in the brace next to the fuel selector, through the weldment and out the hole in the fuselage. I then put a slight curve in the aluminum tubing and pushed it through the hose from the selector side until it exited out the fuselage. The hose did a nice job of bending the tubing through the weldment. I then slide the hose off the tubing from outside the fuselage. I did both sides in 30 minutes....
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fuel lines
Tonny
I just finished mine on an RV9A. I initially left about 5 inches sticking out of the fuselage. I mounted the wings first with the fuel tanks off. I was then able to get an approximate measurement by placing the fuel tank above its mounting location on the wing, you can get a tank to fuselage distance and cut off the tubing a little longer than needed. I then mounted the tanks and bent the tubes slightly out of place with the AN fittings and marked my final cut to match up perfectly with the fitting. Remember you should be able to gain a little by pulling the tube out a little if needed. Cut long and work down to the right length. Good luck Oldgeezer RV9A finishing |
On my 7A, the fuel line length between the side skin and the tip of the flare was (is) 3 5/8".
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tubing kinks. Do kinks ruin a fuel line tube run
What if you get a slight kink in the fuel line tubing? Is that bad? I made a nice run from valve to outside of fuselage but then when I went to bend it slightly at the valve end with my hand and pliers I made a slight kink in the tubing. Dang it. Does a kink or two ruin the whole tubing run?
thanks |
No Kinks Allowed.
Besides restricting the flow, a kink weakens the line.
A kink in a fuel line is similar to a scribe line on sheet metal. Over time it will crack with vibration. |
photo of kinks
Are these kinks no good? Or are they scratches that can fly. See third photo on this page.
http://www.mykitlog.com/users/displa...og=96154&row=1 |
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Personally, I wouldn't want them. It's too easy to make new ones without the "scars". Fuel lines in the cockpit is no place for "marginal". |
Replace!
I am with Mell on this! That looks bad.
As the starter of this thread, I never received an answer regarding the length of the tubes and gues what? my "guestimated" return line lengths were not correct. So I just orderded a 2' length of tube from Vans for $ 3,48 yesterday. I would buy new and replace it! Do you realy want to risk getting burned allive, to save as litle as that? Regards, Tonny. |
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