Combustion chamber for reducing the soot emissions

The chamber (10) has a piston (14) sliding in a cylinder closed by a portion of a cylinder head (12), and including a surface forming a bowl (18). The surface has a projecting central pin (20) and a peripheral part (23) surrounded by an annular tracking zone (24). The pin has a cavity (21) concentric with the pin. The cavity has a lever forming a boss (22), and a central injector (30) injects fuel into the chamber.