Engine with piston that overshoots cylinder wall exhaust port

A linear reciprocating engine, comprising:

• a cylinder having a first combustion chamber at a first end thereof and a second combustion chamber at an opposing second end thereof,
• a first cylinder head located at an end of the first combustion chamber;
• a second cylinder head located at an end of the second combustion chamber;
• a double-faced piston slidably mounted within the cylinder and configured to move from a first position in a region of the first combustion chamber to a second position in a region of the second combustion chamber;
• a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber and through the first cylinder head;
• an exhaust port located in a peripheral wall of the cylinder at an axially central region of the cylinder between the first cylinder head and the second cylinder head;
• and
• at least one first gas inlet located in the first piston rod portion, wherein the at least one first gas inlet and the exhaust port are configured to cooperate such that gas introduced through the at least one first gas inlet is evacuated from the cylinder through the exhaust port in the peripheral wall;
• wherein the double-faced piston has an axial length from the first face of the piston to an opposite second face of the piston, the axial length being less than or equal to ½ of a distance from at least one of an internal end of the first cylinder head to the exhaust port and an internal end of the second cylinder head to the exhaust port.