Caterpillar 7N6550 Cylinder Block Assembly

The 7N6550 cylinder block serves as the core structural component for Caterpillar 3306, 3306B, 3306C, G3306, and 1673C diesel engines. Manufactured to OEM specifications, this cast iron block houses the crankshaft, camshaft, and cylinder liners, providing the foundation for the engine rotating assembly. This part number supersedes and interchanges with references 1N3576 (field replacement group), 8N4776, 4P0623, 2P0960, and 7N5456. It is utilized across a wide range of Caterpillar equipment including 966 series wheel loaders, 330 series hydraulic excavators, D6 and D7 series track-type tractors, D250/D300/D350 series articulated trucks, and 3306 generator sets. The block is designed for high compression ratio diesel operation with precision-machined main bearing bores and cylinder bores for liner installation.