I'm still years out from buying an engine, but I'm interested in this conversation too. The IO390 got such a bad reputation (self inflicted by Lycoming in my opinion) by pricing replacement cylinders as high as they did earlier before bringing them more in line with other engines, plus, I don't know if it is warranted or not, but I've heard of cooling problems, and issues with cracking due to the thin-walled cylinders, and there may be more issues. But I may still buy one simply because that's what Van's says around which the plane is designed. It would be nice to start seeing feedback from those who have the skills and courage to depart from the design engine to include the Superior 400 and Titan 370.
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