Cooling system operation (Cooling system - KV6) (page 2 of 2)

The cooling system employed is the by-pass type.

The centrifugal coolant pump is driven from the timing belt by a flat pulley and circulates coolant from the heater and radiator via the heater hoses, bottom hose and the thermostat. Coolant is circulated around the cylinder block and cylinder head, and when the coolant valve is open, the heater matrix. Heater returns through the top hose to the radiator to be cooled by fan assisted ram air.

When cold, the thermostat closes off the coolant feed from the radiator bottom hose and opens the port from the cylinder block. Coolant is drawn via the heater matrix from the top of the cylinder block, this allows some heat transfer to the radiator via the top hose by convection while retaining the majority of the heat within the cylinder block

The siting of the thermostat in the intake, rather than the outlet side of the system provides a reduced warm up time by circulating a small amount of coolant around a shorter tract which also prevents temperature build up within the cylinder head prior to thermostat opening.

As temperature increases the thermostat gradually opens, bleeding cool fluid into the coolant pump and allowing hot coolant to flow to the radiator via the top hose, balancing the flow of hot and cold fluid to maintain normal engine temperature. As the thermostat opens further and the bottom valve closes, the full flow of coolant is drawn through the radiator.

Excess coolant, created by heat expansion, is returned to the expansion tank via the expansion hose.

The radiator is a copper/brass cross-flow type with moulded plastic end tanks and is mounted in rubber bushes directly into the front body member and bonnet locking platform.

Coolant flows through the radiator from the top of the RH tank to the bottom of the LH tank and is cooled by air passing through the matrix. The cooling fans are controlled by the MEMS ECM. When air conditioning is selected, the fans operate continuously.