Abstract: A modification to a multi-cylinder internal combustion engine to automatically restrict the flow of fuel to one group of the cylinders during a first phase of operation in response to a specified vacuum level generated by the operation of the other group of cylinders. In the first phase of operation, all fuel is blocked from entering the inactive second group of cylinders by a modified valving mechanism in the carburetor. In one embodiment of the invention, it is used in conjunction with throttle valve controls for each of the groups of cylinders, blocking not only fuel to the inactive group of cylinders, but also the flow of air to the inactive group.

Abstract: A device for splitting the operation of a multicylinder internal combustion engine to allow the use of one group of the cylinders during a first phase of operation and the use of both the first and second group of the cylinders during a second phase of operation. In the first phase of operation all fuel and air is blocked by a throttle valve from entering the inactive second group of cylinders, causing these cylinders to operate in a vacuum environment. The throttle controlling the second group of cylinders operates in response to the operation of a throttle controlling the first group of cylinders. In an alternative embodiment, the throttle of the second group of cylinders is kept slightly open during the first phase of operation to provide just enough fuel and air to the second group of cylinders to provide power to turn the pistons in the second group of cylinders and reduce the potential drag forces to the active first group of cylinders.

Abstract: A modification to a multi-cylinder internal combustion engine to automatically restrict the flow of fuel to one group of the cylinders during a first phase of operation in response to a specified vacuum level generated by the operation of the other group of cylinders. In the first phase of operation, all fuel is blocked from entering the inactive second group of cylinders by a modified valving mechanism in the carburetor. In one embodiment of the invention, it is used in conjunction with throttle valve controls for each of the groups of cylinders, blocking not only fuel to the inactive group of cylinders, but also the flow of air to the inactive group.

Abstract: An easily installed modification is disclosed for selectively supplying fuel and air to all or only a fraction of the rotors in a multirotor rotary engine for substantially increasing the fuel economy efficiency of the engine while reducing the emission by-products produced by the engine. The modification system includes means for assuring normal engine idling and for assuring adequate lubrication of rotors during time periods when such rotors are not supplied with fuel or air for combustion.

Abstract: A device for splitting the operation of a multicylinder internal combustion engine to allow the use of one group of the cylinders during a first phase of operation and the use of both the first and second group of the cylinders during a second phase of operation. In the first phase of operation all fuel and air is blocked by a throttle valve from entering the inactive second group of cylinders, causing these cylinders to operate in a vacuum environment. The throttle controlling the second group of cylinders operates in response to the operation of a throttle controlling the first group of cylinders. In an alternative embodiment, the throttle of the second group of cylinders is kept slightly open during the first phase of operation to provide just enough fuel and air to the second group of cylinders to provide power to turn the pistons in the second group of cylinders and reduce the potential drag forces to the active first group of cylinders.