Using Components to Fa-cilitate Stochastic Schedulability

An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating. A passage is provided for rich air/fuel mixture terminating at the rear surface of the valve, when closed, with refinements of the passage, shape of the inlet port, and main combustion chamber wall facilitating the flow of the rich mixture into the auxiliary combustion chamber by venturi action. The flow of fresh mixture into the auxiliary combustion chamber through suction scavenges the combustion gas remaining from the prior firing sequence.