Dave’s RV-7A Building Log

I didn’t get anything done on the plane yesterday, as I was busy helping Julie install a brick patio. We got maybe 1/4 of the way done. It was actually nice to work outside, although I was getting antsy to get something done on the plane.

Today I riveted together the base for the fuel pump, drilled it to the floor stiffeners, and installed plate nuts. Clamped down the pump and filter, and bent some of the tubing. I’m right about back to where this kit should have started out.

Since I needed to paint the fuel pump base, I decided to paint some other cabin parts as well. I probably have one or two more batches of painting after this one.

Adele had a soccer game, so I didn’t get too much done. Seattle hit a record high temperature yesterday (88°F at KSEA), so the garage was also a bit uncomfortable. I finished drilling and countersinking the fuel pump base for the angles that are replacing the flanges. I also primed the angles and a few other miscellaneous parts.

I decided it was time to get the high pressure fuel pump figured out. It’s been sitting around half-assembled for too long. The first tube I tackled will hopefully be the most difficult. As I mentioned in this post, a common problem with the fuel pump/filter kit is that one of the fittings on the pump must be moved. The fitting has a nice pre-made piece of tubing on it, but I wasn’t able to re-bend the tubing to make it work. I used the new 180 degree bender to make a replacement. My first attempt was close, but I didn’t leave enough room at the end to slip on the sleeve and be able to get the flaring tool on it. You need a fairly long section (1/2-3/4″) at the end of the tube for that. My second attempt worked great. I was a little worried that I made the bends too wide, but I trial fit the cover with no issues.

The rest of the tubing is rather dependent on the location of the pump relative to the filter relative to the selector valve. Seemed like a good time to clamp the things down. However, I still had the problem where the fuel pump base wasn’t fitting well between my floor stiffeners. Time to fix that. I can understand it being off a little bit, but mine was close to 1/8″ too wide. I tried bending in the flanges and jamming it in there, but the base bowed up and tended to spring out. I noticed that Walter Tondu solved the issue (4/12/04 entry), by cutting off the flanges and riveting on angle stock at the correct width. I talked with Van’s support a few weeks ago on this subject. They said they would look into the issue and that using angle as a fix would work fine.

I cut off the flanges with the band saw and cut a couple of pieces of angle to replace them. I laid out the holes and drilled them and then called it a night. It’s a little frustrating to spend time on something that should have worked in the first place, but it’s better to just take care of it and move on.

I didn’t do much tonight. Getting the empennage disassembled last night kind of wore me out. I did manage to rivet the attach plate to the VS front spar.

I also finally received the 180 degree tube bender. I will not order anything from Amazon “Marketplace” again. It’s basically no better than Ebay–maybe worse. I ordered a tube bender off the Amazon web site. They charged my credit card immediately. I still haven’t received the bender from them, can’t find out the status, and can’t cancel the order. I ended up ordering one from the Sears web site and it showed up in one week. This is the Imperial 370-FH, the model that Walter Tondu recommended. This thing works great. If you’re going the fuel injection route with Van’s high pressure fuel pump kit, you’ll need a 180 degree bender. This is the best bang for the buck.

I tinkered with the bender for a while trying to figure out how to make the tubing runs for the Airflow Performance high pressure fuel pump and filter.

I didn’t do too much today. I tinkered with the rudder a little bit. It looks like I’ll end up making new rudder stops. Rather than start that, I read over the instructions for the cabin frame. I pulled out the raw stock I’ll need and started to cut a few parts.

I went ahead and installed the right brake line. It’s not perfect, but close enough for now. I made sure the lines would clear the cabin covers and the tubing that snakes under the high pressure fuel pump. I’ll tweak it some more later. The first picture shows how I flared the tubing inside the gear mount.

I figured I might as well finish up the tubing. Or at least as much as I can do without mounting the wings. I pulled out some 1/4″ aluminum tubing and snaked it through the gear mount. The tough part was flaring the end by the gear mount. After that it was just a matter of bending it into place with the spring bender.

After several iterations, I finally got the left gear mount installed. I tried to slip a washer behind the gear mount for the lower outer bolt and of course lost it. I had to remove all of the bolts in order to fish out the washer. I also tried some -12 bolts in the lower inside holes, but they really are too short. The -13 bolts looked too long as well, so I added an extra washer under the nut. That worked out perfectly. Access to the lower bolts is definitely challenging, especially while leaning over the side of the plane. Eventually, I got all of the bolts installed and torqued.

Of course the right side was much easier. It took probably 1/4 as long since I already had everything figured out. It’s very cool to have these things installed finally.

I drilled holes in the firewall for the brake reservoir. It’s difficult to judge the location of the outlet hole, so I made a cardboard template to mark the holes. It turned out darn near perfect. I’m going to wait to do the final attachment until I have some ProSeal handy.

After dinner I remembered that I can now do the final installation of the gear mounts. I started with the left gear mount. Since others have said the -12 bolts weren’t long enough, I started with -13 bolts. There seemed to be plenty of them. As it turns out, the bolts seemed a little long for the two lower, inboard bolts. There’s one less layer of metal at that location. I don’t want the nut to bottom out on the grip, so I might swap those out for -12s.

I also had a heck of a time getting all of the holes to line up. I’m not sure why. The mount just didn’t seem to be cooperating. After a few iterations, I finally got all of the bolts in. I used a telescoping magnet to install the washers and a wrench duct taped to a thin piece of wood to install the nuts. That went pretty easy. After snugging down the nuts a little, something didn’t look right. The mount was not sitting flush against the spar web. Then I remembered that one bolt needs a washer between the gear mount and spar. Dang. That’s where I decided to take a break for the night.

Despite the hassles, it feels mighty good to be installing things (I hope) permanently.