The present application relates to a drive and balance mass. In one example, an engine includes, a camshaft, a balance shaft disposed within an interior of the camshaft, and a first gear, intermediate the balance shaft and the camshaft and driving the balance shaft to rotate about a first axis substantially parallel to a crankshaft of the engine in a direction opposite of the crankshaft. In another example, a balance mass and drive for an engine includes, a planetary gear set including a sun gear, a ring gear and a plurality of pinions mounted on a carrier, an input coupled to an input gear of the planetary gear set, a balance mass coupled to an output gear of the planetary gear set, the output gear configured to drive the balance mass to rotate about a first axis substantially parallel to the crankshaft in a direction opposite of the crankshaft.