Abstract: An internal combustion engine comprises a cylinder block having a plurality of main bearing bulkheads, and a skirt section. Each bearing bulkhead is formed with through-holes each of which as an upper end opening to the skirt section and a lower end opening to the bottom surface of the bearing bulkhead. The bearing bulkhead is formed at its bottom surface with a depression. Each of a plurality of bearing caps is installed to the bearing bulkhead in a manner to fit in the bearing bulkhead depression. Additionally, bolts are disposed respectively in the bearing bulkhead through-holes, each bolt having an upper end section located on the skirt section and a lower end section located in the hole formed in the bearing cap, thereby eliminating the need for excess structure on the bearing cap to sharply reduce the weight of the bearing cap.

Abstract: An automotive internal combustion engine comprises a cylinder block having at its bottom section a plurality of main bearing supporting sections, a bearing beam structure secured to the cylinder block bottom section and including a plurality of main bearing caps each cooperating with a main bearing supporting section of the cylinder block, and a beam section securely connecting the main bearing caps with each other, and a support arm disposed on an end portion of the bearing beam structure and rigidly connected to the lower section of a transmission bell housing, thereby effectively suppressing the angular displacement of the cylinder block relative to the transmission bell housing.

Abstract: An internal combustion engine comprises a cylinder block including cylinder barrels, and main bearing bulkheads each having a bearing section; main bearing cap sections respectively secured to the bearing bulkheads so that each main bearing cap section and the corresponding cylinder block bearing section associate to constitute a main bearing for rotatably supporting a crankshaft; and a bearing beam structure detachably secured to the main bearing cap sections to connect the main bearing cap sections with each other as a single unit, the bearing beam structure including a plurality of beam sections which are disposed parallel with each other and extend along the row of the main bearing cap sections, the beam sections being connected with each other, thereby effectively decreasing engine noise while facilitating the handling of the engine parts before assembly.