PRINCIPLES GASOLINE/DIESEL FUEL SYSTEMS - OD1620 - LESSON 2/TASK 2
b. Precombustion Chamber (figure 40). The precombustion chamber is an
auxiliary chamber at the top of the cylinder. It is connected to the main
combustion chamber by a restricted throat or passage. The precombustion
chamber conditions the fuel for final combustion in the cylinder. A
hollowed out portion of the piston top causes turbulence in the main
in mixing with air. The following steps occur during the combustion
(1) During the compression stroke of the engine, air is forced into
the precompression chamber and, because the air is compressed, it is hot.
volume of air.
(2) As the injection begins, combustion starts in the precombustion
chamber. The burning of the fuel, combined with the restricted passage to