L-Shaped Compression Ring

This ring is used mainly in small 2-stroke gasoline engines as a "head land" ring, the vertical arm of the L being flush with the top edge of the piston crown. With gas pressure acting behind the vertical arm, this ring will also seal when in contact with the top side of the piston groove.Besides being used in 2-stroke engines, in some cases it has been installed in automotive diesel engines in order to minimize crevice volume in the combustion chamber.