I've built round track engines with pistons that had an L-shaped top ring that put the top of the upper compression ring even with the top of the piston. The top ring groove had to be specially machined to accommodate them. The guy with more money than brains who commissioned the engines insisted on using them, and I was never able to get a measurable increase in HP or torque on the dyno compared to engines with conventional rings. I was glad to take his money and do it his way, however. He also had me build a few engines with "zero-gap" rings- - - - -same result, all they did was give him something else to brag about at the bar all of us went to after the races were over on Saturday night.
"A fool and his money are soon parted!"
Jerry
