[sweater914]

having overhauled an aviation engine(O-300-D) coking is not something you what to find in the oil pan, the operating temps were on the mark to, he didn't talk about shock cooling, when you're in cruise flight and about to descend to your destination people had the habit of cutting the power to idle and diving at the ground, aluminum heads don't like a going from a cozzy 400deg to 180deg in 15 seconds, they crack with about a $1200 bill to fix it, food for thought