Abstract: A piston (2) is of refractory materials, particularly for a compression-ignition engine of the type having a head (4), a skirt (6) and their mutual fastening means. According to the invention, this skirt (6) is formed entirely of a refractory material and has two semicylindrical parts (18, 20) each of which has ribs (22) and a semispherical cavity (36, 38). After assembly, the cavities form a ball joint seat for the small end of a piston rod along a plane containing the longitudinal axis (14) of the piston (2). Application is to compression-ignition engines with high efficiency.

Abstract: Process and apparatus for the rapid warmup and thermal regulation of the lubricating oil (18) of an internal combustion engine of the type cooled by a cooling fluid (12) with a high specific heat and slight viscosity such as a water-additives mixture, circulating around the cylinders (6) or liners (8) of this engine. According to the invention, this process consists in a heat exchange between this cooling fluid (12) and lubricating oil (18) at the upper zones of these cylinders or these liners, this oil (18) being able to pick up the calories coming from the cylinder head (2) of this engine to transfer them to this cooling fluid (12).Application: particularly to cooling and lubricating of internal combustion engines.

Abstract: Each cylinder of a slanted, in-line, overhead valve, internal combustion engine has intake and exhaust valves with axes which extend radially from and perpendicular to the camshaft axis. The camshaft axis is above an inclined plane which includes the central axes of the cylinders, and the valve axes are mutually divergent to intersect this plane at different angles.

Abstract: The present invention provides liner for internal combustion engines of the compressed type, in particular for Diesel engines with precombustion chambers. In the liner, the thickness of the compressed portion is reinforced while maintaining a reduced interaxial distance between cylinders by providing two opposed longitudinal flats perpendicular to the plane of the cylinders. The resultant reduced thickness of the liner is compensated for by a connection of the flats to the surface of the liner by concave round offs which form reinforcements of thickness on either side of the thinnest zone. Longitudinal reinforcing ribs, essentially equidistant with each other and the reinforcements, are distributed on the periphery of the liner.