Category: Firewall Forward

Added Ammeter Shunt

August 18, 2021 – I decided to add the ammeter shunt.

In my research about the VPX addition to the airplane, I had read that an ammeter shunt is not required. What I inferred from that is that I would get an ammeter reading from the VPX. While that is true, the indication appears on the VPX page on the Dynon, and not on the engine bar on the main Dynon screens. You can select battery voltage specifically from the VPX to be displayed, but it doesn’t appear that there is that option for amps. The theory is that you can monitor battery voltage for a charge on the battery.

I decided that having an amp reading would give a better indication of charging health, so I installed the shunt. The hardest part of this was  installing the shunt on the firewall. I found the wires from the EMS box and ran them out through the firewall and across to the right side.

Then I installed the shunt and connected the wires. The shunt is in the wire from the ANL60 fuse to the VPX. I haven’t run the engine again since, but I get a 10 amp discharge with power on the airplane, which agrees with the reading on the VPX page.

Time: 2:45

Loose Ends…and Oshkosh!!!

August 5, 2021 – Little things need to be done; waiting on my interior from Classic Aero.

I mentioned in my last post that I had some issues from the first engine run. Some of them I chalk up to a total lack of experience on my part. This entire project has been a learning experience…

I had a few leaks after that first run.

Since the run was right before Oshkosh, I had to wait until after to address those issues. This year was my bride’s first time there. She was a good sport. I think she enjoyed it…she says she’ll come back next year when the RV goes up.

At Oshkosh I bought a union to streamline the manifold pressure installation. I had previously used a piece of the manifold that Van’s sells to use for oil pressure, fuel pressure, etc. I never liked that installation. Here’s the new one:

I also had an issue with RPM. Turns out I neglected to wire for it! So I used the RPM lead for the Dynon EMS and ran it to the tach output on the right PMag. I also investigated the issue with #4 cylinder. It was totally cold during the first run. I disconnected the fuel line at the injector and ran fuel into a bottle. While I had that open, I removed the injector. I could see right through it, so it wasn’t clogged. Put it all back together and rolled the airplane outside.

Well, between a bit of flooding and a low battery charge, we couldn’t get a good start. Back inside, I put the battery tender on it and went home.

The next morning I rolled it outside. Got it started, but it didn’t run well. The RPM indication worked, and #4 cylinder was working. However, I had very little throttle travel before the RPM was very high. The engine was happy around the 2000 RPM point, but anything less than 1400 it barely ran. I couldn’t precisely control the throttle because it was VERY sensitive. I also had the prop control full aft in low RPM. My unfamiliarity with constant speed props led to this.

I shut down and rolled back inside. I did a little research and talked to some people. It was pointed out that Dynon has a setting for the pulses per revolution that it sees from the mag. PMags put out 2 pulses per revolution, and the Dynon default setting was 1. Therefore, the indicated RPM would be twice the actual RPM. Kind of makes sense; It ran happily at 2000rmp, that would really be 1000rpm. I found that setting in the Dynon and changed it to 2.

Took it back outside for a third try. WOW! It ran like butter. RPM indications were more in the real world. I had the prop control full forward. At 1800rpm or so I pulled the prop control to get the oil to it. It took 2 tries, but then the prop moved. Awesome! The RV grin is beginning to show up!

Later on I installed the spinner…

…and the dataplate.

I walked around a bit and found some bolts without nuts on them. Fixed those.

The to-do list is very short now. Like I said, I expect to have the interior soon.

Time: 4:45

Engine Run!

July 22, 2021 – A momentous day!

It’s time for an engine run. I rolled the airplane out to pre-oil. I had the lower plugs out and I pulled the coil wires on each P-Mag. Got in and turned the engine over. I did two 5-second cycles. No oil pressure yet. After the second try, I noticed that I was reading 1 PSI. So I knew the third time would be the charm. Sure enough, as soon as the prop started turning the oil pressure shot up.

I pushed the airplane back into the hangar and started to prep for the run.

While I was doing this I had some “help”. No seriously, these guys at the airport have been a huge support throughout this project and I appreciate everything they do, including their close supervision…  🙂

I installed the lower plugs, found some bolts that needed to be tightened, and went over the entire engine compartment and the cockpit.

After lunch we rolled it back out and tied the tail to a truck.

It started on the second blade!

I have some things to deal with.

  • I had no RPM.
  • It appears that the #4 cylinder was pretty much just along for the ride.
  • There are a few small oil leaks.
  • I have some brake leaks; one inside and one at the left brake.

Here’s the video:

Time: 5:00

Engine Prep

July 22, 2021 – I did some things on the engine to get it ready for the first engine run.

Since I was ready to service the engine with oil, I replaced the stock drain plug with a quick drain.

I installed all of the Skybolt fasteners in the cowling. They provide temporary rubber retainers, so I’m using those until the cowl gets painted. If they don’t last long, I may use the permanent metal rings and buy new ones when it comes time.

I’ve also been trying to figure out how I was going to deal with the sniffle valve in the bottom of the cold-air sump. The valve comes down right between the two crossover exhaust pipes. I slightly bent the tube out of the valve, then used an aluminum tube and a piece of fuel line. We’ll see how long it lasts.

Time: 2:50

Started Gear Leg Fairings

July 22, 2021 – While I’m waiting to do my engine run and later tasks to get ready for inspection, I started on the gear leg fairings.

The drawing for the leg fairings contains a full-scale template for each RV model. I chose to use measurements instead of cutting up the sheet.

The fairings are held tight by a hinge that is installed inside the fairing.

I’m pretty sure I’ll have to trim the total length of these fairings. There’s some interference between the fairings and the brake lines at the lower end that should be relieved by trimming the fairings. That trim should be covered by the wheel pants.

I also started the wheel pants.

the first part of this job is to sand the fairing halves so they fit nicely together. I also drilled the holes for the screws.

I also trimmed the openings for the tires. I took measurements off of another RV-7.

I’m at a stopping point on these. I don’t need these to fly, and Oshkosh is around the corner. I also need to look into jacks for the airplane, since the book calls for the airplane to be level and off the ground.

Time: 9:05


July 2, 2021 – Today I serviced the brakes.

I started by making the links that connect the rudder cables to the pedals. These are made of steel. I still wasn’t really sure how long to make them, so I made them according to the drawing, which still leaves it open to where the pedals are set. It’s still kind of hard to tell, but the pedals appear to be in a good position. If I have to do it again when I get my seats, I will.

A friend had an as yet unused ATS brake servicing tool, essentially a garden sprayer. This has fittings used for brake servicing and bleeding. I also put a barbed AN fitting in the top of the reservoir to catch overflow.

In the second picture you can see the fluid in the lines at the pedals.

The smell of 5606 took me back to my C-5 days. We used to bathe in this stuff.

This went very easily. Connect everything, pressurize the pot, then open the valve. It took a couple of tries to get fluid with no air out of the top. It doesn’t appear that I have any leaks. When I go back in a couple of days I’ll try the pedals and see how they feel.

Time: 5:00

Avionics and Wiring

August 10, 2020 – Just slogging through the avionics.

Engine CHT and EGT

I knocked out the EGT and CHT wiring so I could have some visual progress. Dynon provides spade terminals to match the harness wires which are already terminated. I allowed for service loops with each wire, and I tried to offset each one to reduce the bundle size when it’s all done.

I covered each connection with heat shrink. These are pretty solid.

Then I gathered the wires into bundles, one on each side of the engine.

Other Engine Indications

I connected the Red Cube fuel flow transmitter and the oil temp.

Power to VPX

I connected the wire from the ANL fuse that provides power to the VPX and therefore the rest of the avionics.


I’m using the Van’s Adahrs mount. This mounts the Adahrs just forward of the next bulkhead aft of the baggage compartment wall. I made sure it was level to the canopy rails before I drilled it.

I put the 3 fittings in the Adahrs and thought it would be easier to install the unit in the bracket before it went up in the tailcone.

Ummmm, no.

The bracket is pop-riveted into place, and I couldn’t get my riveter to some of the fasteners. So I laid there and removed the Adahrs so I could get to the rivets, then reinstalled it. I’m actually pretty sure I’m going to have to remove it again so I can get the Skyview network connector attached.

GPS Antenna

I made a bracket for the GPS antenna that attaches to the engine mount aft of the baffle. I didn’t want the antenna on the glareshield, and with the Adahrs in the back, there was no really ideal place to mount the GPS externally. If I figure something different, this bracket is not a huge commitment.

Com Radio Trays

I decided to mount the Com radios front and center on the sub-panel bulkhead.

Time: 23:15

Panel continues

July 15, 2020 – Work continues on the panel and avionics.

I started the connection for power to the VPX. This wire will run from the ANL fuse to the power lug on the VPX.

I located and installed the EMS module for engine management. I decided to drill a hole in the sub-panel for a length of conduit so all the EMS wiring can run straight from the firewall back and come in right next to the EMS module.

Here’s the wires coming through the firewall.

I decided to label all the wires in this bundle, so I can just grab the wires I need for a particular component and finish the wiring. I found the pinout and wire list for the engine sensor connector and rang out each wire. This confirms that the pinout is correct, and leaves out the guesswork.

I relocated the manifold pressure sensor from inside the cockpit to the outside, so I don’t have air hoses running through the firewall, only wiring. Then I found the appropriate wires for the sensor, and terminated and installed them.

Time: 9:20

Installed Engine Sensors

June 25, 2020 – I also installed the fuel and oil pressure sensors.

Dynon released a service bulletin for their Kavlico sensors. I called them since my sensors were still brand-new and in the packages. Since I’ve had them for more than a year, they really couldn’t help me. They also said, however, that the Service Bulletin was released with an abundance of caution, and that I could install mine and just keep an eye on them. That seemed reasonable to me.

Time: :20

Installed Plug Wires

June 25, 2020 – I ran the plug wires on the engine.

I don’t have the plugs in yet, so I’ll probably have to adjust the wires a bit to clean this all up. For the lower wires I used clamps on the lower screws of the valve covers. I used a couple of automotive wire looms to keep wires straight behind the engine.

The upper wires need to be secured. On the right side the wires will run straight to the plugs from the baffle fairlead. On the left side I added clamps to the existing clamps for the fuel lines where they are secured to the pushrod tubes. I made spacers to separate the clamps.

Time: 2:00

Finished Cowl Foil

June 25, 2020- I finished installing the foil in the lower cowl.

I got a roll of foil from Van’s, but for some reason I didn’t order quite enough. OK, it was enough to cover the fiberfrax I got from Spruce. I wished I’d gotten a little bit more of that as well. But it’s in the important area. I ordered a different foil from Summit Racing to finish the rest of the cowl.

So I laid down the fiberfrax, and put the foil over it. The hard part of this was getting the fiberfrax to lay down tightly around curves while I installed the self-adhesive foil. There are a few air gaps, but that should be OK.

The foil I got from Summit was different from the Van’s material, but it should be fine. Here’s the whole cowl covered:

I edge sealed the foil with resin.

Time: 1:30

Made New Starter Cable

May 29, 2020 – I didn’t like how my starter cable was routed, so I made a new one.

Here’s how I originally had it. Kind of hard to see but you are looking for the thick white cable with the red heat-shrink end on it.

The cable ran under the starter, with a lot of potential for rubbing.

I ran the new cable straight back behind the starter, then across to the right side. The cable I made could have been maybe and inch or so shorter, but I can live with the gentle bend it has now.

The pictures show the routing from the starter back around to the start contactor. None of the clamps are tight. They will be tightened later on.

I made a stainless steel bracket for the clamp in the third picture. This is front and center on the sump.

Time: 3:20

Continued Prop and Spinner

May 29, 2020 – I addressed the issues surrounding the prop installation.

There were gaps between the spinner inner surfaces and the spinner back and front plates. This would show itself when I tightened the screws and the spinner would press in. This would cause cracking paint at the very least.

The drawings say to build up fiberglass at the mating surfaces inside the spinner. So I taped off the surfaces so I could get the spinner back off afterwards.

I slathered a resin mixture with flox inside the spinner cone at those locations and installed the spinner, tightening the screws to the point where they were tight but not pressing in.

After it was cured, I had some fun getting the spinner off, but it did come off. I sanded as much excess material out of there as I dared. It’s kind of ugly inside, but it worked. The gaps are filled.

After that, we pulled the prop back off so I could address the issues I found when we first installed the prop.

The ramp for the baffle on the right side was hitting the flywheel. I removed about 1/2″ from that leading edge.

I also turned the main alternator bolt around so the nut faces forward. I found out that with the bolt head facing forward, it couldn’t be pulled out all the way if I had to replace the alternator.

We reinstalled the prop.

I bought the Anti-Splat prop wrench to torque the prop.

After I torqued it all I safetied the prop. I used little pieces of nylon tubing to protect the parts of the flange where the safety wire would cross over.

Time: 5:20

Cowl Foil Prep

May 29, 2020 – I started getting the cowls ready for foil.

I’m going to install Fiberfrax and foil to help protect the cowl from heat and oil. I ordered foil from Van’s and they are out of stock at the moment.

I coated the cowl interiors with resin, and painted them white.

Time: 2:00