An internal combustion engine, including a plurality of pistons, a plurality of cylinders, and an output shaft, wherein the pistons are arranged for reciprocating motion within the cylinders, driven by combustion, and the pistons are coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the engine includes a first cylinder bank and a second cylinder bank, wherein drive for a camshaft of the first cylinder bank from the output shaft is at one end of the output shaft, and wherein drive for a camshaft of the second cylinder bank from the output shaft is at an opposite end of the output shaft.