More stuff
Some progress on the cooling puzzle:
Plugging all of the holes in the baffles raised my pressure from 2.8 to 3.2 in. H2O, and reduced my CHT from 485F to 465. Installing baffles (actually, ramps) in front of the front cylinders, increased pressure from 3.2 to 3.5 inches, and reduced CHT(#4) from 465F to 445F, while raising #1 CHT from 320F to 370F. Drilling 1/4 in. holes in the baffles to avoid making a hot spot on the front(exhaust valve side) of the #1 cylinder lowered the CHT of #1 from 370 to 335F, without raising the #4 temp. It appears that the airflow to the rear cylinders is getting interfered with, perhaps by the geometry of the upper cowl or the stiffener ridge on the rear of the nose bowl. More experiments to come, though it's getting difficult to maintain the same ambient temperatures, as the season progresses...
The biggest difference was flying my friend's cub, which was the same as mine, except for leakier baffle seals and a 56 inch sensenich, whereas mine is a 54 inch. The pressures were much different. And, the CHT's were lower, but I haven't yet been able to calibrate his gage. The differential pressures were lower than mine, WHEN THROTTLE WAS BACK, but 4.2 inches with cruise power. With my sensenich or with my 41 inch Borer, there was very little difference with power. So a climb prop seems to be an aggravating circumstance. Living in the high desert has to be another....