A V-type 8-cylinder four cycle internal combustion engine has a bank angle of 90 deg. and employs a double link type piston-crank mechanism for transmitting the force of each piston to a crankshaft. The double link type piston-crank mechanism comprises an upper link that has one end pivotally connected to the piston, a lower link that is rotatably supported by a crank pin of the crankshaft and has one end pivotally connected to the other end of the upper link, and a control link that has one end pivotally connected to the other end of the lower link and the other end pivotally connected to a cylinder block. Preferably, the crankshaft is of a single plane type in which all of the four throws are in a common plane.