Precombustion chamber gas engine

A precombustion chamber gas engine comprising:

• a main-chamber forming portion forming a main combustion chamber;
• a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes;
• and
• an ignition device disposed at an upper portion of an interior of the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance,
• wherein, in a plan view, the precombustion chamber has a near-ignition region in which the ignition portion is disposed and a far-ignition region opposite to the near-ignition region, the near-ignition region and the far-ignition region being separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion, and
• wherein
• the plurality of nozzle holes includes a specific far nozzle hole which is at least one nozzle hole in the far-ignition region and a specific near nozzle hole which is at least one nozzle hole in the near-ignition region, and a distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of the specific far nozzle hole connected to the precombustion chamber is shorter than a distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of the specific near nozzle hole;
• or
• the plurality of nozzle holes includes a specific near nozzle hole which is at least one nozzle hole in the near-ignition region and a specific far nozzle hole which is at least one nozzle hole in the far-ignition region, and a distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of the specific near nozzle hole connected to the precombustion chamber is shorter than a distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of the specific far nozzle hole.