I'm studying the JPI data from my recent trip to Key West and back to
Wisconsin. One thing stands out.

A sudden drop of 60 degrees EGT and rise of 30 degrees CHT on one cylinder
while all other cylinders remain rock solid stable.

After an extended period of idling at KEYW waiting for a clearance and then
an amended clearance and then a second amended clearance (20+ min) while
aggressively leaned, we performed a second run up to check for fouled plugs
and everything was normal.

Looking at the JPI data for this leg of the flight shows the #1 cylinder on
the left engine reading the lowest EGT and lowest CHT for that engine during
runup, but during takeoff it jumped to the hottest EGT while remaining the
lowest EGT. It remained the hottest EGT for approximately 1 hour and 30
minutes of flight at which point it dropped 60 degrees EGT and gained 30
degrees CHT. This brought the EGT for #1 back into it's "normal" position
as 2nd coolest between #3 and #6, where it had been on most previous and
subsequent flights.

Since this "event" I flew 6+ more hours back to Wisconsin and another 2
hours yesterday shooting approaches. No abnormalities noted.

I can understand a sticky intake valve causing a high EGT then a drop to
normal levels if the valve returns to normal operation, but what's with the
rise in CHT?

Curious.
Jim