Abstract: This invention relates to a sub-combustion chamber of an internal combustion engine, which includes a ceramic hot plug in a hot plug installation hole in a cylinder head, wherein a small clearance is provided between the hot plug and the installation hole to ensure better heat insulation and thus to greatly improve starting performance, combustion efficiency and reliability of the engine. This invention also relates to a sub-combustion chamber, wherein the hot plug can be easily inserted and secured in the hot plug installation hole.

Abstract: An intake burner is disclosed for use in an internal combustion engine having an air intake system including an air intake tube, comprising an outer tube adapted to be attached to the air intake tube, a heater mounted in the outer tube and made of a ceramic material with a heating resistor embedded therein. A holder surrounds the heater in spaced relation thereto and together with the heater defines a vaporizing and a combustion region around the heater for vaporizing supplied fuel along a surface of the heater and for burning vaporized fuel supplied from the vaporizing region. Fuel feed means directs fuel into the vaporizing region around the heater, and a support member attaches the heater to the outer tube.