Two-stroke reciprocating piston injection-ignition or compression-ignition engine

A two-stroke reciprocating piston engine comprising:

• a cylinder having a cylinder bore and a cylinder wall;
• a cylinder head mounted to said cylinder;
• a piston mounted in the cylinder bore for reciprocating motion between a top dead center position and a bottom dead center position
• a combustion chamber, defined by a crown of the piston at top dead center and the cylinder head, said combustion chamber symmetrically shaped and centrally located in the cylinder bore symmetrical with respect to an axis of the cylinder bore;
• at least two valved inlet ports having orifices positioned in the cylinder head symmetrically with respect to the axis, said inlet port orifices connected to receive pressurized oxidizer charge;
• at least two unvalved exhaust ports having apertures positioned in the cylinder wall symmetrically with respect to the axis, said exhaust port apertures exposed with the piston proximate the bottom dead center position and operatively positioned with respect to the at least two valved inlet port orifices for forced gas exchange in the cylinder;
• and,
• at least one fuel injection device introducing fuel into the combustion chamber symmetrically with respect to the axis.