Engine assembly including combustion chambers with different port arrangements

An engine assembly comprising:

• an engine block defining a first cylinder bore and a second cylinder bore;
• a first piston located in the first cylinder bore;
• a second piston located in the second cylinder bore;
• and
• a cylinder head coupled to the engine block, cooperating with the first cylinder bore and the first piston to define a first combustion chamber and cooperating with the second cylinder bore and the second piston to define a second combustion chamber, the cylinder head defining a first intake and exhaust port arrangement in communication with the first combustion chamber and defining a second intake and exhaust port arrangement in communication with the second combustion chamber, the first intake and exhaust port arrangement including only a single exhaust port in direct communication with the first combustion chamber and the second intake and exhaust port arrangement including two exhaust ports in direct communication with the second combustion chamber so as to extend directly from a wall of the second combustion chamber;
• further comprising a third piston located in a third cylinder bore defined by the engine block, the cylinder head cooperating with the third cylinder bore and the third piston to define a third combustion chamber and defining a third intake and exhaust port arrangement in communication with the third combustion chamber, the third intake and exhaust port arrangement including only a single exhaust port in direct communication with the third combustion chamber, the two exhaust ports of the second intake and exhaust port arrangement being permanently connected to intake ports of the first and third intake and exhaust port arrangements to deliver all of the exhaust gasses from the second combustion chamber to the first and third combustion chambers and the single exhaust port of the first and third intake and exhaust port arrangements being exhausted to the environment without delivery to any of the combustion chambers.