andrewr
if you have an engine at peak EGT and you make it richer, which by your example means it will get cooler, why then does it get hotter (CHT) when the EGT is falling? And once past about 50 or so dF CHT will drop again.
When you get the concept here, the rest of my answer will make sense.
Not trying to be a smart ass, just want you to challenge the thought processes.
Creamie is onto it.