The compression ratio of an internal combustion engine is adjustable in a stepwise fashion, such as by pivoting an extension of an eccentric connecting rod bearing. The projection extends into a chamber defined by a portion of a connecting rod coupling portion of a connecting rod assembly. Liquid is delivered to one side of the projection and removed from the opposite side of the projection to move the projection and thereby the eccentric connecting rod bearing from one position corresponding to one compression ratio to another position corresponding to another compression ratio.