Various embodiments provide a method of varying engine displacement. The method includes determining a change in a stroke distance of the engine required to obtain a pre-determined volumetric change in a displacement of the engine. The method includes machining a top surface of a crankcase so as to remove a height of material from the crankcase. The height is calculated to correspond to the change in the stroke of the engine required to obtain the volumetric change in the displacement of the engine. The method also includes coupling the crankcase to an engine block portion of the engine.