Fuselage

Thanks to some helpful information given to me by Dan Benua, I felt confident to go ahead and install the fuel line fitting that penetrates the firewall. The Andair fuel pump and filter assembly instructions show a fitting that they make for this purpose, but it's five times as expensive as the one Vans recommends and Vans doesn't stock it. I didn't know if there was something special about it or if there is some reason I would have to have it. So I went over to Vans and talked with them about this, and upon their recommendation I bought the standard AN fitting they recommend.

UPDATE: November 2012 - I know Vans recommends a standard AN fitting here, and there are probably thousands of RV's flying out there with them, but later on I decided that I'm uncomfortable with aluminum parts on the engine side of the firewall. Especially one having do to with fuel. In the unlikely event of a fire in the engine compartment, this fitting could melt in seconds. This could happen fast enough that you aren't really aware of it until it's too late. Where does a scenario like that leave you? Your high-pressure fuel pump is pumping fuel like crazy right into the inferno. Not only that, but there's now also a breach in the firewall right into the cabin. You're not having a good day at that point. If your thinking is similar to mine, get the steel fitting here. Van's doesn't carry it, but you can get it at Aircraft Spruce and other sources, I'm sure.

Here it is, installed in the firewall. Below, a closeup shot. Installation was easy enough. Drill a hole, deburr, and install the fitting. I have a big thick washer on each side to stiffen it, since the firewall is thin.

Here's the aft side inside the fuselage. Now I have a starting point and an ending point in the cabin for the fuel line, so I can proceed.

UPDATE: May 28, 2010. I haven't been comfortable with the washers used on this fitting as stiffeners. It just didn't seem adequate to me. The plans show a stiffener riveted to the firewall here for the fuel pump for a carburated engine installation. But I was in the dark about what to do in my case because the information I needed for a fuel-injected system isn't in any of the drawings I have at this point. Andair's drawings don't show a stiffener here either.

So I wrote to Vans and sent them these pictures, and Joe Blank emailed me a copy of drawing number OP-32. It shows the details for an IO-360 fuel system. He said I'm into the firewall forward part of the project, which explains why I don't have the drawings yet. Apparently this drawing comes with either the firewall forward kit, or the finish kit. At any rate, I followed the plans on drawing OP-32 and replaced the washer aft of the firewall in the cabin. I made a stiffener from some .063 sheet and riveted it to the firewall. It's all on my page from May 28th. I still don't like the aluminum washer on the forward side of the firewall. But that seems to be standard practice. I'm going to see if I can find a steel one to replace it.

UPDATE #2: November 28, 2012 - My discomfort with all of this was well placed. In spite of the drawing, I still didn't get it. The stiffener is supposed to go on the engine side of the firewall, and it gets riveted to some of the rivets on the vertical stiffener angle as well as to the firewall. I went back and studied OP-32. It doesn't say anywhere on the drawing that the doubler goes on the engine side. BUT... you can figure that out if you study it long enough. A little note on the drawing would have been nice. Anyway, check out my work from this link to see the doubler I fabricated and riveted on here.

<< Previous | Home | Next >>