RV-14 Build – Page 5 – Building a Vans RV-14

Alt Air and Fuel Controller

Posted on September 3, 2024 by Neal

The gasket for the fuel controller arrived today, so I went ahead and installed the fuel controller and final torqued the nuts.

Following the engine maintenance manual, I torqued the nuts to 17 foot pounds (204. Inch pounds). The manual assumes there is no adapter, which there is, but this seems like the right value for the size studs that I’m installing onto.

With that done, I worked on the alternate air installation.

The alt air is a backup air intake for emergency use if the aim air intake were to become blocked (ice, bird strike, etc). There is a door on the side of the snorkel that can be opened with a control inside the cockpit. The standard Vans design doesn’t allow the alt air to be closed once it’s opened, so you’d have to take the cowl off to reset it if it were ever pulled. That’s ok, but it means you can’t test the mechanism as part of a run-up before takeoff.

Of course someone had solved this problem and come up with an alternative door design that can open and close using the cockpit control. The only difference is the door itself, it mounts onto the standard location without any modifications. This is what I’m going to install.

I needed to buy a hole saw because I didn’t have anything big enough. The plans called for a hole that is 2 11/16 inches in diameter. The closest diameter I could find at harbor freight was 2 5/8, and when I drilled the hole, it came out slightly over-sized, which was perfect.

Some of the instructions are a bit confusing, but carefully reading and following the steps made sense eventually.

The inlet is glued into position using epoxy.

Fuel controller installed and final torqued

Page 255 in the manual, explaining the torquing instructions

After cutting the hole, it was exactly the size I needed

The alternative door. Seems to be a good design

Gluing the inlet onto the side of the snorkel

Because of the geometry, and the nut plate, there’s a gap to fill around the edge of the flange

Snorkel fitting

Posted on September 2, 2024 by Neal

Today I worked on fitting the snorkel, completing a few more steps.

With the fuel controller covered in plastic, I placed the snorkel on the flange, and then assessed the alignment at the air filter end, where it attaches to the baffling. The instructions warn that small changes at the fuel control unit can have a large impact on the alignment at the baffling. While true, I found that I needed to take a uniform amount off the fuel control end to get the other end to line up. In total, it was about 3/8 of an inch longer than it needed to be, and after carefully sanding it down, the alignment worked out well. I had to disconnect the oil return line to complete this step, and continually bend it out of the way to avoid interference with the snorkel. I’m hoping that the replacement line I ordered will clear the snorkel, because I’m proceeding with fitting the snorkel before I have the new line in-hand.

Once everything fit, I drilled alignment holes in the air filter end of the snorkel, clecoed them, then marked out the excess snorkel to trim. Then I could take the whole assembly off the airplane and trim the snorkel. I used a hack saw to cut about half an inch off the end of the snorkel, then carefully filed it down until it was flush with the shelf on the air filter holder.

I could then install it back on the airplane, and mix up some epoxy glue to seal the gap between the snorkel and the air filter holder.

Marking the fuel controller end of the snorkel for trimming

Checking the alignment of the snorkel against the fuel controller flange

Checking the alignment of the air filter end of the snorkel with the baffling. The goal is to eliminate any side loading on the baffling, by trimming the opposite end of the snorkel

After trimming the snorkel and carefully filing it to be flush

After sealing the gap around the snorkel with epoxy glue

Snorkel fitting

Posted on August 31, 2024 by Neal

With the fuel controller in place, I was able to test fit the snorkel. Unfortunately I ran into an interference issue, but after some further investigation I found this is a known issue. I ordered a new oil return line for the #2 cylinder from Aircraft Specialty, as they have solved the problem by making a custom tube that doesn’t protrude as far forward. Kit #13 from their firewall forward hose kits: https://www.aircraftspecialty.com/rv-14.html

I also heard back from Airflow Performance, and they sent a doc that has some useful RV-14-specific install info, and confirmed I needed to order a gasket. $2 gasket, and $10 of shipping, it should be here in a couple of days.

RV-14 Mixture Throttle cable pictures.docx Download

The snorkel resting in position as an initial test

The interference issue with the oil return line. The snorkel needs to move aft about 1/4 inch to line up. Rather than restricting the oil flow by modifying the fibreglsss, a new oil return line solves the problem.

Some people have reported interference with the starter solenoid, will have to see how it goes once this is in it’s final location

Baffle Tension Rods

Posted on August 30, 2024September 1, 2024 by Neal

This week I chipped away at the baffle tension rods over a series of evenings. I didn’t actually have a die for cutting the threads, so I had to order one from Aircraft Spruce. These were fairly easy to make, and came out looking good. Some more practice with cutting threads might have helped, but I got the hang of it pretty quickly. When bending the rods I used a block of wood with a slot cut in it to stop the rod rotating, which allowed me to bend both ends of the rods in the same axis.

Installing the rods was fairly easy. I cut a few lengths of 1/4 inch tubing to help prevent chaffing, although there weren’t many areas where interference is possible. Once I had the tubing slid over the rods and positioned correctly, I used some RTV to bond the tubing onto the rod.

With new crush washers in hand I also took time to install the remaining baffle hardware, and torqued everything.

Cutting threads on the tension rods. I used Boelube to lubricate

Two examples of the tubing installed on the front right rods. This is before I smeared the rod in RTV and slipped the tubing over

Fuel controller

Posted on August 28, 2024 by Neal

Tonight I unpacked the fuel controller and installed it on the engine. This required some research, as there isn’t any documentation from the Lycoming or Airflow Performance in the box. I found some help on Vansairforce, and was able to find the Airflow Performance manual. I ended up emailing them anyway, because I don’t have a gasket in the box.

For now I installed the unit using the temporary nuts to hold it in place, so I can test fit the snorkel.

Baffle adjusting

Posted on August 25, 2024 by Neal

Today I spent time adjusting the front baffles to fit nicely against the engine case. The front left baffle took the most adjusting, and after several iterations I was happy with the fit.

With the baffles fitting nicely I went ahead and installed the hardware and torqued everything up. I have run out of -40 star washers, so I ordered some more and put tape on the screws that were missing washers.

Front baffles

Posted on August 23, 2024 by Neal

Tonight I test fit the front baffles. The front right baffle was the easiest to install, and looks to be a good fit. The front left was more challenging, but after disconnecting the oil return line, I was able to get it into position. This one will need a little adjustment to properly conform to the engine casing, and a couple of corners that need some easing.

In the process of test fitting the front baffles I noticed that I had made an error with the front center bracket. Just like the aft bracket, I had misread the drawing and had it on the left side instead of the right side of the centerline. Then I noticed I had the bolt installed from left to right, instead of right to left, on both brackets. It’s probably not a big deal, but it always makes me nervous when I miss something or find an error. What else did I miss?

I fixed the errors with the bracket, installed the hardware and torqued the nuts.

Front baffles

Posted on August 23, 2024August 24, 2024 by Neal

Over the last few evenings I’ve made a little progress on the front baffling.

I riveted together the parts, and applied RTV where instructed. The RTV strips are to reduce chaffing on the engine cylinder cooling fins. RTV is also used to help glue the mesh in place covering the cabin hot air intake.

These are ready to be test-fit onto the engine and trimmed (if necessary).

Front left baffle with RTV strips applied

More Baffling

Posted on August 19, 2024 by Neal

Tonight I worked on the front baffles, including the air ramp. Dad had already made progress drilling and deburring parts, and installing nut plates. I picked up where he left off and completed a page of steps.

Aft Baffling Install

Posted on August 18, 2024August 20, 2024 by Neal

Today I installed the aft baffles on the engine. I started by picking up some high temp RTV from AutoZone. The RTV is used to provided a cushion for the baffling where it will vibrate against the engine. I masked up the aft baffling, roughed it up with sandpaper, cleaned it, and then smeared RTV in the specified locations. This was then left to dry for a few hours.

Later in the day I installed the aft baffles, and looked to areas where it was rubbing against the case. I found a few locations, and marked them with a sharpie. Then I uninstalled it all, filed down the offending areas, and then reinstalled for (hopefully) the final time.