Patent ID: 6973907

Claim:
A cylinder block for an internal-combustion engine, comprising: an upper block wall surrounding an upper part of a cylinder of the engine, and including first and second upper side walls on first and second sides of the cylinder; a crankcase including first and second side walls formed, respectively, on the first and second sides; first and second head bolt bosses formed, respectively on first and second sides, each head bolt boss projecting from the upper block wall and including a head bolt hole opening in a top deck of the cylinder block; a cap-mounting bulk portion extending between the first and second side walls of the crankcase, and arranged to support a crankshaft rotatably with a bearing cap; first and second bulk connection portions projecting, respectively, from the first and second side walls of the crankcase, to the cap-mounting bulk portion, and thereby connecting the cap-mounting bulk portion, respectively with the first and second side walls of the crankcase, each of the first and second bulk connection portions being formed with a hollow portion extending in a vertical direction of the cylinder block; and first and second connecting ribs extending in the vertical direction and connecting the first and second bulk connection portions, respectively, with the first and second head bolt bosses.