Engine with profiled combustion chamber - has swirl inducing bowl in chamber to reduce hydrocarbon emissions during start=up and light loading

摘要

The spark plug (12) tip is encircled by small secondary chamber (10) amounting to appro. 1/1000 of the swept volume which has single opening (9) amounting to 1/1000 of the piston area in the direction (3) of the vortex. The secondary chamber consists of a bowl fixed in a borehole of the cylinder head floor and is only bombarded by a fuel stream at smaller swirling intensities of the air in the lower speed range of the engine. The design achieves improved mixture formation under these conditions.