A CRANKSHAFT FOR A V-TYPE INTERNAL COMBUSTION ENGINE

A crankshaft (1) includes a first to a sixth crank pin (4146), a first to a fourth main journal (21-24) and a first to a ninth crank arm (61-69). At least the first, the second, the eighth and the ninth crank arms (61, 62, 68, 69) have respective integral counterweights (61', 62', 68', 69') for balancing the crankshaft (1). In order to reduce bending stress on the areas where the second and the eighth crank arms (62, 68) are connected to the respective pairs of adjacent crank pins (41-42, 45-46), the axial dimensions of the first and the ninth crank arms (61, 69) are reduced, being substantially the same as those of the adjacent crank arms (62 , 68) in order that the axial length of the two end spans of the crankshaft is the same as that of the intermediate span. In order to balance the crankshaft (1), two additional counterweights (71, 72) are arranged outwardly of the end journals (21, 24) and their axial dimensions are comparable to those of the end crank arms (61, 69).