We did a top overhaul on my O235 C1B and there was a choice on which way the oil scraper ring went on the skirt. I know if it was incorrect it would cause dry cylinders. If your pistons require that extra ring on the skirt you’ll have to find the documentation. For some engines the chamfer went up and other engines the chamfer went down. I sold that plane and the documents went with it. Sorry not much help but wanted to alert you about the choice of ring orientation.