Gas engine cylinder head, and a method of retrofitting the head with a precombustion chamber unit

摘要

The cylinder head has a conventional spark plug, therein, for engine start-up, and has a precombustion chamber unit mounted therein as well, for cleaner, more stable normal running of the engine. The method defines the reaming out of spark plug apertures in the head to accommodate the installation of the precombustion chamber unit.