I finally found a way to spot cracked pistons without pulling the jugs

Been working on Lycoming engines for about 8 years now and always dreaded pulling cylinders just to check for cracks. A senior mechanic at our shop in Tucson showed me you can use a borescope with a 90 degree mirror attachment to check the piston skirt through the spark plug hole. Caught a hairline crack on an O-360 last Tuesday that would have been a total failure within 20 hours. Anyone else tried this trick or got a better way to inspect pistons without tearing down?

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mary_kelly1mo agoTop Commenter

Huh, that's a pretty clever trick with the mirror attachment. I'm just wondering though, how often do you actually find cracks that are that serious? In my experience, most hairline cracks aren't going to turn into a total failure in 20 hours like that. Might be worth double checking the severity before you start tearing stuff apart based on a borescope find. Your mileage may vary though.