With a better roll trim and improved engine cooling plenums to provide better airflow to cylinders 3/4, I took her for another flight. There were broken clouds down to ~4000′, so I climbed up to 10,000′ to get on top. First off, I noticed the improved roll trim out of the gate. I could now do a hands-off climb – big improvement. After I reduced power and started my cruise climb, I did notice cylinders 3/4 were cooler, but during an aggressive climb out #2 started to get hot and I had to put the nose down and keep 100kts to keep it cool. Once I got to 10,000′ (took some negotiating around some nice, fluffy clouds) and leveled off, temps were ok, but as soon as I tried to lean to peak, #2 got too hot, 3/4 probably could have handled leaning and #1 was nice and cool (too cool?). Below is the plot of the CHT’s for the flight. The blips in all CHT’s are when I talk on the radio (Dynon has an issue with the thermocouple’s picking up the PTT). You can see right from the initial climb out #2 is hot. It’s getting plenty of airflow, so I’m thinking its a fuel flow problem – I suspect #1 is getting more than its share of fuel, too. You can see the bumps in the middle when I’m at cruise and I try leaning it to peak and have to back off. At the end of the cruise when things settle down you can see the big differences, particularly b/w cyls 1/2.
I’m going to measure the fuel flow thru each and see if I’ve got a blocked injector or line.
Here’s the CloudAhoy log for the flight.
