The lubricating oil pump, code P51501-23, is a vital heart of the MAN L21/31 engine’s lubrication system, responsible for circulating oil under controlled pressure to all critical moving components. By ensuring a continuous supply of clean, pressurized oil to bearings, pistons, camshafts, and gears, the pump minimizes friction, prevents metal-to-metal contact, and supports efficient heat removal. Its robust design and precise flow characteristics make it essential for engine durability, especially in demanding marine environments where uninterrupted reliability is mandatory.