Prechamber ignited engine and operating methods therefor

A method of operating an engine comprising:

• moving a piston coupled to a crankshaft in an engine from a bottom-dead-center position toward a top-dead-center position in a cylinder in the engine;
• directly admitting a prechamber fuel containing methanol into a prechamber ignition device fluidly connected to the cylinder;
• directly admitting exhaust into the prechamber via an exhaust feed opening fluidly connecting an uncooled exhaust conduit to the prechamber;
• autoigniting the prechamber fuel to produce jets of gases from the prechamber ignition device;
• and
• igniting a main charge of a fuel in the cylinder via jets of gases produced via the autoignition of the prechamber fuel.

An engine system comprising:

• an engine having a cylinder formed therein, an intake port, an exhaust port, and a piston movable in the cylinder between a bottom-dead-center position and a top-dead-center position to increase a temperature and a pressure in the cylinder;
• a fuel system including a fuel supply of a liquid fuel containing methanol;
• an ignition system including a prechamber ignition device having a prechamber, a fuel port fluidly connected to the prechamber, an exhaust feed opening fluidly connected to the prechamber, and at least one ignition port fluidly connected to the cylinder;
• and
• the ignition system further including a fuel admission valve positioned fluidly between the fuel port and the fuel supply, and an exhaust admission valve positioned fluidly between the exhaust feed opening and the exhaust port.