Thermostat 78C (Safety lead)

We have recently manufactured this 78C thermostat. We have become increasingly aware of engine problems being caused by engines running too hot. We feel that this is partly caused by the ethanol content of modern fuels but we are definitely seeing an increase in problems related to the bottom half of the engine overheating. We believe that this thermostat, which opens 10 degrees lower than the standard thermostat, may help to alleviate some of these overheating issues. It also contains the safety pellets that will let coolant bypass the thermostat in the event of overheating, preventing damage. 

The very early SY models (prior to VIN 2832) were fitted with thermostats that started to open between 79.5C and 83.5C. From 1966 (VIN 2832) an 88C thermostat was fitted which started to open between 85C and 89C. This thermostat is designed to open between 75-79C and to be fully open at 88C. Alongside this we have developed a tool to allow you to test the opening temperature of a thermostat should you wish to do so. If you fit this 78C thermostat please be aware that the engine will run cooler and on later (post 1987 models) this may bring on the Check Engine light.

Please note that these are built to the correct original drawings which allow a full minimum opening travel distance of 9.5mm - unlike other thermostats that we have seen in the marketplace.