Abstract: A cylinder block assembly for an internal combustion engine having a cylinder block and a plurality of cylinders includes an oil port in each of the cylinders. An annular groove is located in each cylinder wall so that oil flowing from the oil port flows into the annular groove to lubricate the skirt of the piston. An opening may be located in the piston so that oil flowing from the oil port flows into and through the piston opening when the piston is at a predetermined position, thereby directly injecting oil into the piston to lubricate the wrist pin of the piston.

Abstract: Oil injection apparatus and methods for injecting oil directly between the cylinder sleeves and the pistons of both cylinder banks in a v-type engine are described. In one embodiment, and with respect to each cylinder, an oil port in the engine block extends to an annular groove in the cylinder wall. An oil pump supplies lubricating oil to the port via a conduit, and under the control of a control unit. In operation, if the piston is thrust into the cylinder wall at the location of the groove when oil is being injected, the oil flows into the groove and is dispersed as the piston moves past the groove on the next stroke. If the piston is not thrust into the cylinder wall at the time oil is introduced, the oil flows into the cylinder and is dispersed by the piston.