I took the Teal for a spin today. It is equipped with an O-360 Lycoming. It has a bar graph engine monitor. When operating about 50 degrees rich of peak lean at 2500' feet, the application of carb heat caused an indicated EGT rise of one to three degrees, and did not change the relationship from hot to cool cylinder. It caused a CHT rise of 2 degrees once stabilized. There was about a 1 inch MP decrease, so it did result in a power reduction.
At peak lean, the results seemed to be about the same - nothing dramatic.
I tried to operate lean of peak, but the engine just would not run smoothly. It stumbled badly, so I stayed over the water to be safe. No matter how precisely I leaned past peak, it would stumble right away, and the EGT would drop right off. Richen up, and it ran like a top. The temperature range of leaning seemed to provide about 150 degree EGT rise from rich to peak, All of the bars moved about the same about, with the hottest and coolest always remaining the same.
All of this was done at 2000 feet, 16C, with no vizible moisture, and an engine with 33 hours since overhaul.
I therefore suggest that on this engine, carb heat has little to do with EGT or CHT, affects power as expected, and is unlikely to be a cause for detonation.
I hope that this informal test helps a little.
Pilot DAR