Abstract: A cast cylinder head for an internal combustion engine. The cylinder head includes a first surface, a rear surface, and an intake passageway. The first surface is adapted to be connected to a cylinder housing, and the rear surface extends from the first surface. The intake passageway is in the cylinder head and extends from an inlet on the rear surface toward an outlet on the first surface. The intake passageway includes a straight portion that extends from the rear surface and that includes an axis. The included angle between the axis and the first surface is approximately thirty-five to forty-five degrees.

Abstract: An internal combustion engine has an integral cylinder head, a one-piece connecting rod, and a crankshaft disposed at the interface between the first engine housing and the second engine housing. In an overhead cam shaft embodiment, the cam shaft drive means includes first and second gearsets of cross-helical gears. Also directly mounted to the cam drive shaft are the oil slinger, the centrifugally-responsive speed governor components, and the auxiliary power take-off shaft. This arrangement eliminates the need for additional shafts and subassemblies. In another embodiment, both the crankshaft and the cam shaft are disposed at the interface between the two engine housings to decrease manufacturing and assembly costs. The crankshaft and/or cam shaft bearings are formed integral with the engine housings to eliminate the need for separate bearing components.

Abstract: A balance system for an internal combustion engine or the like includes a counterbalance weight pivotally mounted to the crankcase and driven in a reciprocating manner by a link assembly connecting the weight to an eccentric on the crankshaft. The pivoting weight not only counterbalances the piston acceleration and deceleration forces but also cancels the torsional forces created by the weight as it pivotally moves through an arc in response to piston movement. This is accomplished by locating the center of gravity of the balance weight between the piston bore centerline and the stationary pivot of the balance weight itself. This location for the center of gravity causes a torque to be generated by a force couple created by the piston inertial force vector, the balance weight interial force vector, and the distance between them. This torque counteracts the torque generated by angular acceleration of the balance weight itself, to thereby substantially eliminate all torsional vibrations.

Abstract: An engine-balancing system for balancing the primary forces of single cylinder and in phase in-line multi-cylinder piston engines. The balancing system includes rotary, auxiliary counterweights mounted on the exterior of the engine block for rotation about fixed axes that are parallel to and spaced from the crankshaft axis and positioned at diametrically opposite sides thereof. The combined centrifugal forces of these auxiliary counterweights are preferably equal to that of the conventional crankshaft-carried counterweights. The auxiliary counterweights are drivingly-connected with the crankshaft by a flexible double-sided timing belt that is trained over sprockets of the same diameter coaxially fixed with respect to the crankshaft and with each of the pair of auxiliary counterweights so that the pair of auxiliary counterweights turn at the same speed as, but in the opposite direction from that of the crankshaft.