Abstract: An internal combustion engine includes a crankshaft having a first end and a second end opposite the first end. The crankshaft defines a crank axis and is rotatable about the crank axis. The internal combustion engine also includes a camshaft that defines a camshaft axis and is rotatable about the camshaft axis. The internal combustion engine further includes a cam drive assembly that is operable to transfer rotation from the crankshaft to the camshaft, a balance mass rotatable about the crankshaft, and a balancer drive assembly operable to drive the balance mass through the cam drive assembly.