Opposed-piston cylinder bore constructions with solid lubrication in the top ring reversal zones

A cylinder, comprising:

• longitudinally-spaced exhaust and intake ports;
• a bore with a surface for supporting sliding movement of a pair of opposed pistons, the bore comprising a solid lubricant material disposed in each of a first and a second top ring reversal zone;
• and
• at least one injector hole positioned between the top ring reversal zones.

A cylinder liner for an opposed-piston engine, comprising:

• longitudinally-spaced exhaust and intake ports;
• a bore with a surface for supporting sliding movement of a pair of opposed pistons;
• a coating layer comprising a solid lubricant material disposed respectively in a first top ring reversal zone of the bore;
• a coating layer comprising the solid lubricant material disposed respectively in a second top ring reversal zone of the bore;
• and
• at least one injector hole positioned in a zone of the bore between the first and top ring reversal zones.

A method of coating discrete ring reversal zones in the surface of the bore of an opposed-piston cylinder, comprising:

• forming at least one annular groove in the bore surface that is aligned with a ring reversal zone and located in the vicinity of a hole location in a sidewall of the cylinder;
• applying a layer of solid lubricant material to the bore surface and extending at least over the annular groove;
• and,
• removing solid lubricant material from the bore surface while leaving the solid lubricant material in the at least one annular groove.