Ignition enhancement chamber for internal combustion engine

In an internal combustion engine including a combustion chamber and piston means for cyclically compressing a gaseous fuel mixture in said combustion chamber,

• the improvement comprising
• control means to regulate ignition firing of a combustible fuel and air mixture in said combustion chamber, and particularly adapted to regulate ignition of a mixture in which the ratio of fuel-to-air is less than stoichiometric, said control means including:
• an enclosed substantially fluid tight auxiliary chamber of lesser internal volume than said combustion chamber but at least 5% of the volume thereof,
• said auxiliary chamber being in gas-flow communication with said combustion chamber but spaced therefrom,
• isolator means defining restricted fluid passage means interposed between said combustion chamber and said auxiliary chamber to obviate ignition-induced flashback from said auxiliary chamber to said combustion chamber,
• said isolator means also being operative partially to insulate said combustion chamber from said auxiliary chamber thermally,
• packing means of heat retentive material dispersed interiorly of and distributed throughout said auxiliary chamber to provide a high surface area-to-volume ratio within said auxiliary chamber, thereby to enhance heat transfer and distribution,
• said surface area to volume ratio within said auxiliary chamber being at least 10:1.