Fuel Lines Chapter 26

[DaveLS]

Has anyone fitted/installed the fuel lines before installing the belly skin?

Some templets could be made to accurately locate the fuel pump, fuel valve, and flow scan for fitment and the skin braces, F1204Z, in the gear channel (F1204 assembly) would insure the correct lengths. The forward belly skin, F1272, and lower firewall, F1201C, could be clecoed in place as well. Before riveting the belly skin on the system blocks, F1276C, system block studs, MS35206-248,and snap bushings would all have to be installed

Just askin......

Thanks, Dave

[daveyator]

The fuel lines connect to the pump, floscan etc. how can they be installed until those parts are fitted? They really are pretty straightforward with the belly skin on. Before the side skins makes sense, though in hindsight, I probably wouldn't have bothered. I found the lengths in the plans to work nicely for me.
Dave Hastwell
120485

[DaveLS]

Fair questions Dave. Here is my thinking:

1) Why: Fitting and installing the fuel lines might be easier before the belly skin is installed. With the belly skin installed the work is done in realitively confined akward spaces.

2) How: Instead of the belly skin locating the pump, valve, and flow scan for the fuel line fitment, temporary templets would.

A little more explanation of the suggested build process.


Think of the templets as small pieces of belly skin that temporally mount these parts and are attached to nearby under structure, i.e. ribs/bulkheads. This puts the pump, valve, and flow scan accurately in their correct location. These templates could be made by match drilling small pieces (6x6 in?) of al sheet to the belly skin where these parts mount. After match drilling, clico the temples to the ribs/ bulkheads and then clico the fuel system parts to them. After fitting/ installing the fuel line remove the templets and install the belly skin.


My questions are: 1) would this work, and 2) what elce needs to be considered.


-Dave

[lpeeds]

I did mine by the plans and found it to work quiet well. Sounds like you are trying to complicate something that is fairly simple. Good luck either way.

Paul Eeds
120560
Finishing touches-I hope.

[f1rocket]

As others have suggested before, it might be easier to turn your fuselage on it's side once it is done to install the fuel lines, wiring, and controls. That allows for easier access but more accurate work.

For me, I just followed the plans and it all worked out. Some of the work wasn't terribly fun, but I managed.

[MacPara]

I installed all the tunnel wiring and plumbing while the fuse was on its side. The belly skin was installed and needs to as the fuel valve and the pump are attached to it.

[cactusman]

There was some advice that you install the bulkhead fuel fitting for the fuel return line before the bottom skin. I forgot to do that and am paying the price now - it is a pain after the fact.

The main fuel lines all require several items on the bottom skin to be installed, although the bend down after the bulkhead has me scratching my head.

[f1rocket]

Originally Posted by cactuspilot

There was some advice that you install the bulkhead fuel fitting for the fuel return line before the bottom skin. I forgot to do that and am paying the price now - it is a pain after the fact.

Man, is that ever true. I missed it too.

[cactusman]

Here is a pretty good summary addendum thread...I printed these and try and look ahead and see what still applies as the plans have changed in some instances, but I do think it is pretty good advice to do 28 after 22.

http://www.vansairforce.com/communit...elage+addendum

[Tony_T]

This is the pesky bulkhead fitting that is installed in Sec 28 but should be more easily installed before the bottom skins are on as the guys above found out:


The downward bend in the main fuel line to clear the flap handle can be made with a bludgeon. Ken Scott designed this out of a piece of wood and wrote it up in Rvator #3-2009 when he was building his 12. It is on the table in the picture under the hammer. Make a grove same diameter as the fuel line in the curved end of the bludgeon, place it on the fuel line and whack it. You can practice this on some scrap tubing before doing it on your carefully fabbed up main fuel line. All of this stuff is easily done with the fuselage up on its side as seen here:


It has been 4 years now since I did these things. What fun it was !

Tony