5S6795 Combustion Chamber Fits CAT Fits Caterpillar 3304 3306One New Aftermarket Replacement Precombustion Chamber for Caterpillar (Cat) 3304 3306 Engines This precombustion chamber assembly (also called a pre combustion or antechamber insert) is the separate combustion space in the cylinder head where fuel is first ignited before expanding into the main cylinder. It is a precision fit engine component used in Caterpillar 3304 and 3306 indirect injection diesel engines found across a wide range of Cat