The invention describes an arrangement for causing combustion to take place in an engine of the Diesel type.
According to the specification, in addition to the usual combustion space, there is provided in the cylinder head a small chamber or pre-explosion space in direct and continuous communication with the combustion space by means of one or more ports.
During working, fuel is injected into this pre-explosion chamber by means of a suitable device, and, as the injection is timed to occur slightly before the crank reaches its dead centre, and as the compression is sufficiently high to ignite the fuel, a partial ignition takes place in the above mentioned small chamber or pre-explosion space, complete combustion being prevented by the limited supply or air.
The rise in pressure due to this incomplete combustion causes a rapid discharge of gas through the narrow ports into the combustion chamber, this discharge occurring before any particles of fuel have had time to settle on the walls of the pre-explosion chamber. Combustion is then completed in the main combustion space.