Patent ID: 8430080

Claim:
An Otto cycle internal combustion engine provided with at least one combustion chamber and at least one inlet and at least one outlet with respective valves at the said at least one inlet and at the said at least one outlet respectively to enable fluid material to flow into and out of the said at least one combustion chamber in accordance with the engine cycle operation, and a suction passage leading to the said at least one inlet to conduct the flow of fluid material thereto, the engine further comprising a control valve arranged upstream of the said valve of the said at least one inlet, and being operable to change between a condition in which it opens the suction passage and a condition in which it closes the suction passage, an engine operating position sensor arranged to provide signals indicative of the operating position of the engine, an engine power control, and a variable intermediate position control signal generator, which generates control signals at times respectively between the beginning and the end of each of a succession of inlet valve opening periods of the engine cycle and which is connected to receive signals from the engine operating position sensor and the engine power control and to send the control signals to the control valve, whereby the operation of the control valve can be synchronised with the engine cycle operation in such a manner that in between an opening of the inlet valve and the immediately following closure thereof there is a period in which the suction passage is open and a period in which it is closed, the period for which it is open being in dependence upon the engine power control output.