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.