An engine and a method of operating the engine wherein fuel, intake air, and recirculated exhaust gas provides a first mixture, which is inducted into a first combustion cylinder. The first mixture is combusted in the combustion cylinder to generate a first exhaust gas that applies pressure to a piston within the combustion cylinder, reciprocating the piston and rotating a primary crankshaft coupled to the piston. Fuel and intake air, which provides a second mixture, are inducted into a rotary combustion chamber. The second mixture is combusted in the rotary combustion chamber, wherein the combustion generates a recirculated exhaust gas that applies pressure to the rotor and rotates the rotor and a secondary crankshaft coupled to the rotor. The secondary crankshaft is coupled to the primary crankshaft by a gear mechanism. The recirculated exhaust gas is exhausted into an exhaust gas recirculation loop and recirculated.