Nov 21, 2022     Reinstalled fuel line, autopilot servo and fuel tank - (3 hours)       Category: Fuel System

The new fuel line went in OK -- it might have been about 1/32" long -- but took a lot of finagling to get the threads to engage on the fitting but that was eventually accomplished. Had to remove one control rod to reinstall the Adel (cushioned) clamp then holds it into place and then reinstalled. Then bolted the fuel tank back in place, torqued all fittings to about 87 inch pounds (after calculating for the Crow's foot). I used a torque value of the midway point of the callout for a 3/8" aluminum tube. Then reinstalled the auto pilot servo and control rod. Lots of scrapes on the hand.

  Nov 21, 2022     Constructed new fuel line. Again - (1 hour)       Category: Fuel System

I brought a bunch of tools home so I could work on making a new tank-to-fuel-pump line in relative warmth. I was exceedingly careful with measurements and came up with one I THINK will work. In order to get those measurements right, I did the pump end first, which is a 90-degree bend. That allowed me to place it on the figure in the instructions (27iS-04 Figure 2) to get the reference point for a 20 29/32" mark, which is the beginning of the bend line for the tank end. Then I put the fittings on and flared that end.

Of course, now I can't use a spring bender to make this bend and if I'd made the bend first I wouldn't be able to get the collar on before flaring the tube.

What I was able to do is put the whole thing in a small Imperial tube bender to at least START the bend. I didn't get it quite right, but I got it pretty close.

So where did that nick come from? One of the suggestions the last time I made (remade, actually) this line was to put a bulkhead fitting on and use that for leverage when making the bend. It's possible that it put pressure on the collar which dug into the soft aluminum; I just don't know. But as I said earlier, this is the second nick I've discovered on this line (one I might've made when tightening a B-nut) so I'm going to keep a close eye on this to see if I'm missing anything.

  Nov 19, 2022     Added missing rivets; pulled fuel line - (2 hours)       Category: Fuel System

17 degrees today so I didn't anticipate spending too much time at the hangar; I'd intended only to START the process of pulling the fuel tank so that I could install those four rivets I missed during construction of the center section. But the fuel tank came out easily once I loosened the fuel lines so I pulled it and finished those rivets.

However, I noticed a "nick" in the fuel line just below the collar for the B Nut. This is the second time I've found a nick in this location. Previously I thought maybe a wrench dinged it during tightening. The fuel tank is a really poor design and it's near impossible to get wrenches on the nuts. But on this particular nut, I think it was the collar that pressed into the tubing somehow; possibly while making a bend. I don't know.

But I pulled the fuel line which means I also had to remove the autopilot servo. This is a REAL pain in the neck to make because the Van's instructions don't work; at the tank end it says to make a 21/32" mark and begin a 35 degree bend, THEN flair the tube. You can't; a collar won't fit over the bend and you can't flare with the collar in the place. This has to be done after flaring using spring benders.

I've got enough tubing to make one, maybe two attempts at getting it right. We'll see.

  Aug 27, 2021     Remade tank to vent fuel line - (4 hours) Category: Fuel System

It took a ton of tries and several orders of 3/8" tubing but I was finally able to make a new fuel line for the tank to vent fitting. What a pain in the neck. As I already mentioned, do not follow Van's instructions here, which have you installing the sleeve and nut before making the 38 degree bend at the tank end. This cannot be done. A sleeve will not fit over such a bend. A tube bender won't work because the beginning of the bend is too close (21/32") to the end of the tube. And doing it by hand won't work because you can't get enough leverage.

The solution is to flare the end and install the sleeve and nut, then connect it to a fitting (I used a 90 degree fitting. Then put spring benders over the tube, marking where the 21/32" line is, and then bend by hand, using the fitting for leverage. You can do this in numerous steps, checking your work against the full-scale drawing in the instructions. I found SLIGHTLY overbending made it easier to screw the nut on at the tank end.

Fit that assembly to the tank, and mark the center of the fitting at the valve end. You should also have marked the dimension in the plans from the bend at the other end. This part takes a little trial and error because there are no callouts for the midpoint of that bend and the 180 degree tubing bender I use requires the midpoint of the bend be known.

I used a point to the left of that centering mark to begin the bend and then reinstalled on the tank end to check to see if I was in the ballpark. Then I just "freelanced" it a few times in the tubing bender to get the alignment to the valve fitting right. Then I added the sleeve and nut and flared that end and installed.

It's still a ginormous pain in the neck to torque the nut at the tank end. You can MAYBE -- maybe -- get a wrench on it from underneath if you rotate the control rods out of the way. But you have to be really careful. A crowsfoot doesn't really work here.

I suppose you could remove (detaching at the flaperon end won't work) the control rods for this and reinstall but, holy smokes, what a ridiculous pain in the neck.

Van's should really take another run at the tank design here. Accessibility really suffered when they came up with this one, in order to move the tank from the corner to behind the plane's seats. Not too mention the multiple angles in the tank design, all of which are potential leak points.

  Jun 24, 2020     Fuel prefilter to fuel pump connection - (2 hours)       Category: Fuel System

Warren Starkebaum flew over to KSGS in his RV-7 for an inspection of the powerplant kit and then I had an eye exam to replace the prescription glasses I stepped on the other day and with both out of the way, I started making some of the fuel filter runs as called out in Section 27.

Both came out fine and maybe I won't need that ATO-035x3/8 I ordered. We'll see.

I do have to contact Van's to see if there's a mistake in the labeling of figure 3 in page 11 of Section 27.

It seems to me they've reversed the prefilter end and fuel pump end labels as the prefilter sits inboard of the connection for the fuel pump and, hence, should have the shorter run. Reversing it and it fit perfectly. Pictures attached show what happens if you install according to the instructions.

Will confirm.

  Jun 23, 2020     Fuel pump assembly - (2 hours)       Category: Fuel System

I'm a pretty simple guy but I'm always impressed when fuel lines I built two years ago from the front of the RV-12, with several bends, end up mating perfectly with the banjo fitting on the fuel pump assembly that arrived last week. OK, I probably could have made it 1/16" shorter.

I found a very short piece of ATO-035x3/8 to use to make the two inch run to the fuel drain assembly. It was part of the tank test manometer (which didn't work on this plane because it's impossible to seal up the filler hole). Later, I heard from Van's that it was OK to use that two-foot length in the powerplant kit, but I've got more to make and I'll use it for that before the 8 feet of coil I ordered last night shows up.

I sure hope the new design with sealing washers works because there's a LOT of potential failure points here. I'm being super careful.

This is the old design where the fuel line comes under the shut-off valve instead of looping aft around it so I installed the standoff and firesleeve as directed in the SB to avoid chafing.

That's going to be a tight squeeze there when the tailcone goes on.

There is one electrical connection there and the wiring is apparently in the final subkit. Not sure how hard that would be with the tailcone on but I would like to get aft skin, window, and canopy done at some point. After the cowling maybe.

It's good to be working on the project again.

  Jun 22, 2020     Assembled fuel filter assembly - (1 hour)       Category: Fuel System

I got an obstinate hangar door motor all fixed; that was the sum of my day work at the hangar, but I went back out around 10 and did some more work at night.

Put together the fuel filter assembly (didn't tighten the banjo fittings. I got my Amazon order of Loctite 567. In the far past, Van's recommended Fuel Lube/EZ Turn on fuel line pipe fittings. Now they recommend against it and this product comes highly recommended in the RV universe. Not sure I like it that much.

First, Fuel Lube, applied properly, was super effective, if super sticky. This product takes 24 hours to cure and apparently only really "hardens" in the threads, not on that little amount that is twisted out. We'll see.

I'm going super slow on this part of the build to make sure everything is done properly. I've reviewed ALL of my work on the project so far and reread Section 5.

To that end, I was extra careful on the AN816 fittings etc. were installed finger tight and then given 1/2 turns.

There is a two-foot section of ATO-035x3/8 that comes with the powerplant kit but I don't know if that's specifically for some of the work in this section. I ordered more from Van's after I searched around for some in the workshop. Wasn't sure if tht two-foot section is for something else, so didn't want to use it.

  Jul 19, 2018     Ran fuel lines to the front - (2 hours)       Category: Fuel System

I finished the long return line and filter bypass line which attaches to the manifold up front, tightened the spacer under the two bulkhead fittings and reconnected the fittings (not torqued). I found that you need to countersink the bottom of the plastic "holders" in the main channel in order to get them to fit over the nuts on the studs and sit flush to the floor.

On to the pedals!

  Jul 16, 2018     Installed fuel valve - (1 hour)       Category: Fuel System

Back at the hangar after a couple of weeks away to work Twins games.

Van's swapped out the correct fuel valve for the one they had sent me so I drilled the 1/4" hole and then installed it, the fuel line from the tank matched up just fine. Torqued it to 115 inch pounds and then riveted on the little "locking plate."

I'm also taking off those bulkhead fittings up front to get the spacer plate to fit better. In order to do it, though, I need to buy another open box wrench and grind it down to allow it to work in close quarters.

  Jul 04, 2018     Remade some fuel lines - (2 hours) Category: Fuel System

I had to remake one of the lines I made yesterday because I routed it through the wrong snap bushing.

Also made the return line that connects to the bulkhead fittings and then connected both to the manifold. It's a tight fit all around.

None of the fittings have been torqued; some of these are tough to get wrenches on.

I've got to figure out how to get a wrench on one of the nuts on the bullkhead fitting because the spacer isn't fitting flush and I can tighten the nut any more so that fitting is loose. Design flaw, I think, having the two fittings so close to each other.

  Jul 03, 2018     Started making fuel lines - (2 hours)       Category: Fuel System

I checked with Eric at Van's who said the fuel pump comes with the powerplant kit so he advised running the fuel lines based on the dimensions in the section and then move on to rudders and brakes so that's what I'm doing.

I did some scrap work to remember how to use the pipe bender and made the line that runs from the fuel tank bank to the connectors at the fuel valve (Van's sent me the wrong valve so Eric is sending a new one and I sent this one back).

I can't imagine what this will be like when I put the tailcone on because it's really hard to get to the connector at the fuel tank. Not sure how I'm going to torque it up.

I also made one line that runs from the firewall bulkhead fitting back to the first area under the floorboard and that went well to.

I can flare tubing with the best of them!

  Jul 01, 2018     Section 27: Fit the fuel tank - (3 hours)       Category: Fuel System

The manometer says the pressure mostly held (I'm chalking any reduction to the fillers. So I installed it into the fuselage was a bear because the flanges on a bracket hit the baggage floor cover. So I cut the flanges back a little bit until I could make it fit. Then drilled the #12 hole in the attach bracket and removed the floor cover, added a nutplate and riveted things together

I had previously assembled the connectors at the beginning of Secion 27 but have noticed that the fuel valve referenced doesn't look like the fuel valve they sent (which is basically the RV-7A fuel valve, so I've dropped Van's a note to explain the discrrepancy.

I also installed two fitting in the firewall and used sealant between the bulkhead union. Didn't like the way the nuts don't tighten completely on the spacer nor the inability to get a wrench onto them because they're too close together . Will monitor this location.