Low-noise-level reciprocating piston engine

摘要

A reciprocating piston internal combustion engine comprises an engine block formed with first bearing carrying portions which carry a group of upper generally semicylindrical parts of main bearings for supporting a crankshaft, and a bearing support block secured to the engine block and formed with second bearing carrying portions which carry a group of lower generally semicylindrical parts of the main bearing, so that the engine block is reinforced to prevent generation of engine noises due to low flexural rigidity of the engine block.