An internal combustion engine, the engine comprising: an engine housing having a first wall delimiting a first combustion chamber and a second wall delimiting a second combustion chamber with the first wall and second wall each defining at least a section of a torus; a first piston having a first piston head further delimiting said first combustion chamber, a second piston head further delimiting said second combustion chamber, a pivot arm coupled to a common pivot point having a crank pin; a second piston having a third piston head further delimiting said first combustion chamber, a fourth piston head further delimiting said second combustion chamber, a pivot arm coupled to said common pivot point having a crank pin; a guide frame coupled to said crank pin of the common pivot point and having an open receiving area in which an engaging member couples the guide frame to the pivot arms (22B, 37B) of the first piston and the second piston; and a guiding means that includes two parallel guide columns (93L, 93R) slidably received by the guide frame; wherein said first piston and said second piston are guided along a curved path defined by said common pivot point; wherein said first piston and said second piston move in opposite directions; wherein said pivot arm of said first piston and said pivot arm 37B) of said second piston oscillate about said common pivot point 30); and wherein the motion of the guide frame along the guide columns (93L, 93R) is transferred to the first and the second piston (20, 35); characterized in that at least one oblong plate coupled to said crank pin of the common pivot point is provided; wherein the momentum generated by the movement of the oblong plate maintains the oscillating movement of the first and the second piston (20, 35). an engine housing having a first wall delimiting a first combustion chamber and a second wall delimiting a second combustion chamber with the first wall and second wall each defining at least a section of a torus; a first piston having a first piston head further delimiting said first combustion chamber, a second piston head further delimiting said second combustion chamber, a pivot arm coupled to a common pivot point having a crank pin; a second piston having a third piston head further delimiting said first combustion chamber, a fourth piston head further delimiting said second combustion chamber, a pivot arm coupled to said common pivot point having a crank pin; a guide frame coupled to said crank pin of the common pivot point and having an open receiving area in which an engaging member couples the guide frame to the pivot arms (22B, 37B) of the first piston and the second piston; and a guiding means that includes two parallel guide columns (93L, 93R) slidably received by the guide frame; wherein said first piston and said second piston are guided along a curved path defined by said common pivot point; wherein said first piston and said second piston move in opposite directions; wherein said pivot arm of said first piston and said pivot arm 37B) of said second piston oscillate about said common pivot point 30); and wherein the motion of the guide frame along the guide columns (93L, 93R) is transferred to the first and the second piston (20, 35); characterized in that at least one oblong plate coupled to said crank pin of the common pivot point is provided; wherein the momentum generated by the movement of the oblong plate maintains the oscillating movement of the first and the second piston (20, 35).