Abstract: A primarily oil-fueled engine is disclosed in which the engine compression ratio is established well below the level at which compression ignition of oil fuel will occur and in which the oil fuel charge is ignited by the discharge from a spark ignited, gas-fueled precombustion chamber. The compression ratio and peak firing pressures are similar to those encountered in a gas-fueled engine.

Abstract: The application of an electrostatic field across energy fuels subsequently burned in a reciprocating internal combustion engine improves anti-knock characteristics, thereby increasing available energy for engine operation.

Abstract: An internal combustion engine is normally fueled from a primary source of natural gas. A pressure switch closes upon sensing engine vacuum. A second pressure switch closes at a predetermined low pressure in the primary natural gas source. The closing of these two switches opens a solenoid valve to admit gas from an alternate source to the engine. A check valve prevents gas from the alternate source from flowing towards the primary source. The engine's battery provides electrical energy for the solenoid and the battery is in circuit with the engine's ignition switch.