Abstract: A method for operating an internal combustion engine. The method includes: providing a functional relationship between time rate of change in engine speed, and compression ratio switching engine speed limit; determining time rate of change in engine speed; determining from the determined rate of change of engine speed and the function whether the engine speed exceeds the compression ratio switching engine speed; and commanding the engine to operate at a relatively low compression ratio if the determined time of change in engine speed exceeds the compression ratio switching engine speed limit and commanding the engine to operate at a relatively high compression ratio if the determined time of change in engine speed is less than the compression ratio switching engine speed limit.

Abstract: A method and system for operating an internal combustion engine. The internal combustion engine is operable in a plurality of compression ratio operating modes. The method includes determining a relationship between a base engine threshold load where the high compression and low compression provide substantially the same engine fuel consumption and engine speed. The determined nominal relationship is modified by a factor, such factor being a function of a condition under which such engine is operating, to obtain a modified relationship. The modified relationship is a function of engine speed and the condition has an effect on knock generation in such engine. The modified relationship and engine speed are used in selecting one of the plurality of compression ratio operating modes for the engine.

Abstract: In a vehicular warning system for sensing the approach of severe weather, a pressure sensor generates a first signal representative of the barometric pressure. A computer, coupled to the pressure sensor through the electrical system of the vehicle, generates a second signal responsive to the first signal changing in a time series pattern correlated with a known time series pattern representative of a severe weather system. The computer is coupled through the electrical system of the vehicle to the horn and/or lights for generating warning signals responsive to receiving the second signal, but only when the vehicle is not in the operating mode.

Abstract: An apparatus for controlling and varying the closing force of intake or exhaust valves for an internal combustion engine. Hydraulic system, responsive to a minimum high speed condition of the engine, is used to increase the spring rate of the valve closing springs. The hydraulic system also reduces the spring rate when the engine falls below such speed condition. A spring biased idler pulley is also used to maintain adequate tension on a belt, providing drive to the camshaft for the valves. Adjustment apparatus is associated with the spring biased idler pulley for controllably increasing the spring rate for biasing when the engine speed is above a minimum condition and for decreasing the spring rate when the engine speed is below the minimum condition.