In attempt to correct high CHT in #3 cylinder, I went at the cooling plenum again. This time, opening up the area fore of cylinder 3 trying to make the turn down from the runner from the NACA to cylinder #3 a little more gradual. Before going at it, the plenum was up tight along the cylinder side wall, I removed the fiberglass about half-way down the cylinder wall, and made the transition from there to the runner intake more gradual. I also added an aluminum deflector at the top/side of the plenum to deflect more air down onto #3.
These changes seemed to have made a difference as today I was able to climb out at full power and #3 only got to ~415F. I was pretty aggressive with it, so I think prior to this, it probably would have been at ~430F or higher without these changes. As usual, once I got to cruise altitude, all cylinders came in to about the same temp ~370-380F once I stabilized at ~50deg LOP. I was at 10,000′, so that resulted in about 60%power, 150kts, 8GPH fuel burn. I’ll take that.
The OAT at 10K’ was a bout 42F, so I turned on the heat. It was not excessive, but it did warm the cabin up a bit. I’ve got a lot of leaks, (canard is still not sealed up) tho, so I’ll try it again after I get the cabin sealed better.
Did some more stall testing. I got a nice pitch buck at 50kias.