PURPOSE: To prevent the deformation of a cylinder bore, etc., by allowing the axis line of a bolt for installing a cylinder head onto a cylinder block having a plurality of banks to coincide with the axis line of a bolt for installing the bearing cap of a crankshaft onto the cylinder block.

CONSTITUTION: When a large pressure is generated inside a cylinder 4, an upward force acts onto a bolt 13 on a cylinder head through the cylinder head. A downward force acts onto a bolt 12 on a hearing cap 11 through a piston, connecting rod, crank shaft 5, and the bearing cap 11. Since the axis line of the bolt 13 is arranged in coincidence with the axis line of the bolt 12, the forces acting onto the bolts 12 and 13 are offset each other, and no bending moment is generated on a bulkhead 9, etc. Therefore, the deformation of a cylinder bore 15, etc., which communicates to the bulkhead 9, etc., is prevented, and the consumption of oil and the generation of vibration and noise are prevented, and the increase of the weight of the engine can be prevented.