System for regulating coolant flow in an engine

A fluid regulator for use in an engine coolant system including an engine and a radiator, the fluid regulator comprising

• a fluid-control housing formed to include an inlet port arranged to receive engine coolant from an engine, a radiator port arranged to discharge engine coolant to a radiator associated with the engine, and a radiator bypass port arranged to discharge engine coolant to the engine, the fluid-control housing also being formed to include a fluid-transfer passageway arranged to conduct engine coolant flowing in a radiator loop through the engine and the radiator in the fluid-control housing from the inlet port to the radiator port and a radiator-bypass passageway arranged to conduct engine coolant flowing in a bypass loop through the engine without passing through the radiator from a first thermostat node located in the fluid-transfer passageway to the radiator bypass port, the first thermostat node being located in the fluid-control housing to divide the fluid-transfer passageway into an upstream section arranged to interconnect the inlet port and the first thermostat node in fluid communication and a downstream section arranged to interconnect the first thermostat node and the radiator port in fluid communication,
• a fluid-flow controller located in the fluid-control housing, the fluid-flow controller including a radiator bypass thermostat located at the first thermostat node and configured to divert flow of engine coolant flowing in the upstream section of the fluid-transfer passageway into the radiator bypass passageway for circulation in the bypass loop when the temperature of the engine coolant at the first thermostat node is below a predetermined temperature and into the downstream section of the fluid-transfer passageway for circulation in the radiator loop when the temperature of the engine coolant at the first thermostat node is at least the predetermined temperature, the fluid-flow controller also including a radiator warm-up thermostat located at a second thermostat node provided in the radiator bypass passageway to communicate with engine coolant flowing in the radiator bypass passageway,
• wherein the fluid-control housing further includes a radiator warm-up passageway arranged to conduct engine coolant from the second thermostat node to the downstream section of the fluid-transfer passageway for delivery to the radiator port, and
• wherein the radiator warm-up thermostat is configured to provide means for diverting a stream of warming engine coolant from the engine coolant circulating in the bypass loop and flowing in the radiator bypass passageway from the first thermostat node to the radiator bypass port into the radiator warm-up passageway during an early stage of an engine start-up cycle when the engine coolant is circulating mainly in the bypass loop to cause the stream of warming engine coolant to flow through the radiator warm-up passageway into the downstream section of the fluid-transfer passageway to exit the fluid-control housing through the radiator port so that the stream of warming engine coolant exiting through the radiator port can flow through the radiator and the radiator loop to pre-warm the radiator and any reserve engine coolant in the radiator before the temperature of engine coolant at the first thermostat node reaches the predetermined temperature to cause the radiator bypass thermostat to block further flow of engine coolant into the radiator bypass passageway and direct such flow of engine coolant into the downstream section of the fluid-transfer passageway for circulation in the radiator loop through the radiator.