A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and a switch to change operation of the engine between gaseous fuel and liquid fuel. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off attaches to the carburetor to interrupt liquid fuel upon actuation of the switch from liquid fuel to gaseous fuel.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and a switch to change operation of the engine between gaseous fuel and liquid fuel. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off attaches to the carburetor to interrupt liquid fuel upon actuation of the switch from liquid fuel to gaseous fuel.

A method of controlling a high pressure gas injection internal combustion engine includes injecting, in a first combustion mode, by a first as injection system, a first gaseous fuel into a cylinder of the engine, and accumulating in a container of a second gas injection system excess gaseous fuel from the first fuel system, shifting, in the cylinder, from the first combustion mode to a second combustion mode including determining a value of an air flow related parameter indicative of an air mass flow into the cylinder, determining, based on the determined air flow related parameter value, a value of a fuel flow related parameter indicative of a mass flow of the excess gaseous fuel, and supplying from the container, in accordance with the determined fuel flow related parameter value, the excess gaseous fuel to provide a premix of air and the excess gaseous fuel to the cylinder.

A method of controlling a high pressure gas injection internal combustion engine includes injecting, in a first combustion mode, by a first as injection system, a first gaseous fuel into a cylinder of the engine, and accumulating in a container of a second gas injection system excess gaseous fuel from the first fuel system, shifting, in the cylinder, from the first combustion mode to a second combustion mode including determining a value of an air flow related parameter indicative of an air mass flow into the cylinder, determining, based on the determined air flow related parameter value, a value of a fuel flow related parameter indicative of a mass flow of the excess gaseous fuel, and supplying from the container, in accordance with the determined fuel flow related parameter value, the excess gaseous fuel to provide a premix of air and the excess gaseous fuel to the cylinder.

A fuel line for use in a fuel-carrying vehicle designed as a one-piece multi-chamber line having at least two separate fuel-carrying lines each forming a chamber. A first chamber carries fuel in a first flow direction and a second chamber carries fuel in the first or a second flow direction. Also proposed is a correspondingly adapted connection piece for joining to such a multi-chamber line.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and a switch to change operation of the engine between gaseous fuel and liquid fuel. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off attaches to the carburetor to interrupt liquid fuel upon actuation of the switch from liquid fuel to gaseous fuel.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and a switch to change operation of the engine between gaseous fuel and liquid fuel. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off attaches to the carburetor to interrupt liquid fuel upon actuation of the switch from liquid fuel to gaseous fuel.

A fuel additive system includes a fuel supply having an intake manifold, a fuel tank, a fuel supply line, and a fuel delivery system. A fuel additive supply is fluidly connected to the fuel supply for adding fuel additive to fuel from the fuel supply. The fuel additive supply includes a fuel additive tank and a fuel additive supply line connecting the fuel additive tank to the fuel supply.

A multi-fuel rail apparatus for an internal combustion engine communicates fuel from 10 a first fuel source and a second fuel source to a plurality of fuel injectors. Each fuel injector receives fuel from the multi-fuel rail apparatus through a branch connection for each fuel. The multi fuel rail apparatus has a first elongate member including a first longitudinal bore spaced apart from a second longitudinal bore and first and second fuel inlets for fluidly communicating first and second fuels into the first and 15 second longitudinal bores respectively. There is a branch connecting structure for each fuel injector along the first elongate member for fluidly connecting the first and second longitudinal bores with respective branch connections from respective fuel injectors.

A multi-fuel rail apparatus for an internal combustion engine communicates fuel from 10 a first fuel source and a second fuel source to a plurality of fuel injectors. Each fuel injector receives fuel from the multi-fuel rail apparatus through a branch connection for each fuel. The multi fuel rail apparatus has a first elongate member including a first longitudinal bore spaced apart from a second longitudinal bore and first and second fuel inlets for fluidly communicating first and second fuels into the first and 15 second longitudinal bores respectively. There is a branch connecting structure for each fuel injector along the first elongate member for fluidly connecting the first and second longitudinal bores with respective branch connections from respective fuel injectors.