Self-charged four stroke one-cycle combustion cylinder for internal combustion engine

An internal combustion engine comprising:

• a cylinder defining an internal space segmented into a pre-compression space and a combustion space, wherein a bore size of said cylinder is greater than that of a crank-shaft piston housed within;
• an occupying structure situated within the cylinder, acting as a secondary piston and configured to reciprocate in unison with the crank-shaft piston;
• an oil socket located adjacent to the occupying structure, the oil socket comprising a first outer sleeve connected to an upper part of the occupying structure and a second inner sleeve connected to a lower part of the occupying structure, wherein the second inner sleeve is designed to enclose the crank-shaft piston, facilitating reciprocation therein;
• wherein the oil socket is configured for direct lubrication from an engine oil sump to the cylinder's internal surfaces without contaminating the combustion space and configured for supporting exhaust scavenging;
• and
• an air intake assembly capable of directing air into the pre-compression space during a power stroke, with the air being inductively transferred to the combustion space during a retraction stroke via the use of one-way valves.