Controlled cooling system for a turbocharged internal combustion engine

A cooling system for a turbocharged internal combustion engine having heat exchange radiator means, liquid coolant to absorb heat from said engine, pump means to pump said coolant through said cooling system, fan means to force air in heat exchange with said radiator means, and turbocompressor means to increase the density of a combustion air charge, which cooling system comprises:

• temperature control valve means to direct a portion of said liquid coolant discharged from said engine to said radiator means and to direct a portion of said liquid coolant to bypass said radiator means in response to the temperature of said liquid coolant after discharge from said engine;
• liquid subcooler heat exchange means to lower the temperature of said liquid coolant by passing in heat exchange with forced air from said fan means;
• flow control valve means to direct a portion of said liquid coolant discharged from said radiator means to said liquid subcooler heat exchange means and the remainder of said liquid coolant to said engine wherein said flow control valve means includes a flow sensor to sense liquid coolant and signal means in communication with said flow control means to control the portion of coolant to said subcooler means;
• aftercooler heat exchange means to lower the temperature of said combustion air charge discharged from said turbocompressor means by passing said combustion air charge in heat exchange with said liquid coolant from said subcooler heat exchange means;
• and
• fan speed control means to control the speed of said fan in response to ambient air temperature and in response to load on said engine.