Piston cooling system for an internal combustion engine

A piston cooling system for an internal combustion engine having a crankshaft, a plurality of pistons connected to the crankcase shaft, and a crankcase housing partitioned by a plurality of partition walls into a plurality of partitioned sections, and a pressurized lubrication fluid circuit integrated with the crankcase housing for the circulation of lubricant therethrough and including a plurality of longitudinal bores each extending through a respective one of the partition walls of the crankcase housing generally coaxially with one another and generally parallel to the crankshaft, the piston cooling system comprising:

• a plurality of bores each formed in a respective partition wall and communicated with the pressurized lubricant fluid circuit;
• and
• a plurality of spray nozzles, each spray nozzle being mounted in a respective longitudinal bore and oriented for spraying lubricant onto the underside of a piston and being communicated with a respective bore such that each spray nozzle is fluidly communicated with the pressurized lubricant fluid circuit.