Why is my new engine running so much hotter than my old engine?

Q: I fly a Cessna 182S registered HP1401. It has a Lycoming IO-540-AB1A5, 3 blade prop. Sea level OAT is 90°F or so year round. It had a single probe analog CHT display connected to cylinder #1, which always remained around 320°F. I then installed a digital engine monitor, which showed the rest of the […]