An internal combustion engine includes first and second common rails each having a metering or pressure regulating valve, with the valves settable at different pressure values from one another. Rotors are each sealingly and rotationally received within a respective cavity to define at least one combustion chamber of variable volume. The engine includes for each of the rotors a pilot subchamber in communication with the respective cavity, a pilot fuel injector in communication with the pilot subchamber, an ignition element positioned to ignite fuel within the pilot subchamber, and a main fuel injector in communication with the respective cavity at a location spaced apart from the pilot subchamber. Each main fuel injector is in fluid communication with the first common rail and each pilot fuel injector is in fluid communication with the second common rail. A method of combusting fuel in an internal combustion engine is also provided.