<<George Braly says: Something is "wrong".   Unexpectedly HOT induction air
should not make the CHTS get hot enough to require a power reduction when
one is in icing conditions.>>

I will certainly weigh in with George on this one.  Unfortunately, no one
seems to have an inlet air temperature sensor to know exactly how much the
induction air temperatures go up.  I would suspect that the temperature at
the throttle body wouldn't go up by more than 50F and probably not that
much.  My experience testing this same effect on automotive engines suggests
that the temperature change of the inlet air IN THE CYLINDER, which is where
it counts, is usually about half the temperature change at the throttle
body.  This is because of the heating of the air as it goes through the
intake port.  So with a charge temperature that goes up 25 degrees I can't
imagine that the CHT would go up by even close to 25 degrees.  For those
that have manual alternate air doors it would be easy to test on a nice
clear day.  What I can believe is that the same ice that bothered everything
else also builds up on the cooling air inlets, obstructing cooling air flow.
You can't see it and it will be melted by the time you get out of the
airplane on the ground, but I'd guarantee it is there.

Gary Casey