When a piston (12) is located at its top dead-center, a combustion chamber (CC) (20) has the shape of a trough with a circular periphery vertical in cross section to the piston's direction of movement. On a compression stroke, as the piston approaches its ...

The auxiliary control valve has a section (32) of the air intake channel widened out in the flow direction for providing a valve seat (50), with an annular flow cross-section (40) defined between the widened section and a flow body (36) arranged coaxially ...