SQUARE RINGS IN A ROUND HOLE
We have a quick trick to use while checking ring gaps on odd engines that you may not have a ring squaring tool for, and/ or the pistons are not of a flat top design. Set your digital-dial calipers for the depth you want to check the rings, lock the set screw, and carefully use the butt end of the calipers to square the rings in the bore. Check them a few times around the circumference as they will move around a bit until they are nice and square. This will get Gilligan off the island if you don’t have a ring squaring tool that will fit the bore. Also be sure to deburr your rings when finished grinding gaps. We also go a step further on the oil scraper rings as these are steel. We lightly grind a small chamfer with the belt sander on the outside corner of the steel oil rails as these will scratch the bores after some run time. We then lightly deburr the chamfered edge with a scotchbrite wheel on the pedestal grinder, and then finish with a light lap on the top and bottom surface of all the rings to ensure no hang ups on the ring lands. (I can’t take full credit for this procedure. We adopted it from the “Blueprint it and build it right” article written for Engine Builder by the late Joe Mondello.)

Jake Sampson
Sampson Racing Engines
Inver Grove Heights, MN
October, 2014