Ignition combustion pre-chamber for internal combustion engines with constant stoichiometric air-fuel mixture at ignition

An internal combustion engine including at least one combustion chamber and a pre-chamber in fluid communication with said combustion chamber, a method of providing combustion within said combustion chamber comprising the following steps:

• (a) charging said combustion chamber with a first mixture of air and fuel having a lean ratio of air-to-fuel;
• (b) charging said pre-chamber with a further mixture of air and fuel, said further mixture having a ratio of air-to-fuel that is compensated by an amount responsive to the leanness of the mixture used to charge said combustion chamber, the volume of the prechamber, the volume of the main chamber, and the compression ratio of the engine;
• (c) mixing, within said pre-chamber, a portion of said combustion chamber mixture with said pre-chamber mixture to provide a still further mixture having an air-to-fuel ratio that is optimally ignitable while the mixture within said combustion chamber continues to have substantially said lean ratio of air-to-fuel;
• (d) igniting the still further mixture within said pre-chamber to create a flame front;
• and
• (e) propagating said flame front into the combustion chamber to ignite the air and fuel mixture within said combustion chamber,
• wherein said step (b) is performed over at least a large portion of the operation range of the engine.