Flew 0.6 today, I think it was -2F on the ground (edit: metar history shows 2-6F). I added this additional blockoff to the cowl exit:
- Screenshot_20240119-211421-766.png (637.63 KiB) Viewed 1624 times
Climbed to 4500', oil temp stabilized at 165 in cruise. During descent it came down to 155, either if I dove to a higher airspeed or pulled power back. Down by my feet the temperature read 48, and was about 38F on the seat. CHTs were 160-170. They were over 200F in climb.
I also pulled off the orange electrical tape from the wing roots. That tape is a few years old and is shot. I re-taped it with wider 1" tape and reduced the air leaks considerably. I think I'm declaring success. We are going to fly tomorrow and it is supposed to get to 20 as the day's high. I'm leaving the blockoff configuration as is and I'm predicting 185-190F oil temps. If it gets too hot it is only one screw to step down in the blockoff of the outlet, to the prior configuration.
Edit: This new plate screws to the prior plate I showed with 1 screw. The first plate now has a nutplate. The new one hooks onto the hinge pin near the center, where there are no hinge loops. Otherwise it rests on the inside of the cowl sort of. I drilled 3 large clearance holes for the rivets that install the first plate to the hinge. So if it is hot, I can land and remove the new plate with one screw and the original plate is still there.