INVESTIGATION OF MICRO-PILOT FUEL IGNITION SYSTEM FOR LARGE BORE NATURAL GAS ENGINES Scott A. Chase, Daniel B. Olsen, and Bryan D. Willson Colorado State University Engines and Energy Conversion Laboratory Mechanical Engineering Department Fort Collins, CO 80523 ABSTRACT This investigation assesses the feasibility of a retrofit diesel micro-pilot ignition system on a Cooper-Bessemer GMV-4TF two-stroke cycle natural gas engine with a 14” (36 cm) bore and a 14” (36 cm) stroke. The pilot fuel injectors are installed in a liquid cooled adapter mounted in a spark plug hole. The engine is installed with a set of dual-spark plug heads, with the other spark plug used to start the engine. A high pressure, commonrail, diesel fuel delivery system is employed and customizable power electronics control the current signal to the pilot injectors.