A thermostat might be a small part, but it plays a big role in keeping your classic car or truck running at its best.
A thermostat has two important functions…
- The thermostat blocks coolant from circulating through your engine when it is cold. When you first start up your engine you want it to reach its optimum operating temperature. By blocking the coolant from your radiator to the engine, the thermostat helps to accelerate the warming up of your engine.
- Once your engine reaches its operating temperature, the thermostat will open, allowing coolant to travel through your engine. The thermostat will then regulate the flow of coolant depending on the temperature of the coolant itself. This help to make sure your engine stay at the desired operating temperature.
A thermostat therefore is normally closed when you first start up the vehicle. Since it is closed, coolant flow is restricted and the engine can quickly heat up. Once your engine reaches a certain temperature, the heat will melt a special wax that is located inside of the thermostat. This wax then expands and pushes against a small piston which will open the thermostat. Coolant is then allowed to flow from the radiator to the engine.
The thermostat will continue to open further allowing more coolant flow depending on the temperature. If the temperature of the coolant begins to cool, the wax will then contract which causes a spring to close the thermostat. Closing the thermostat will then restrict the amount of coolant that can flow.
American thermostats will have a Fahrenheit temperature rating like 160 degrees or 190 degrees. The number is determined by your engine and other factors like climate. Whatever the rating is, that is the temperature the wax will begin to melt and your thermostat will open. Your thermostat will typically be wide open when the temp reaches 20 degrees above the rating.
Watch this video as Barry Wilson explains the importance of choosing the correct thermostat for a classic car or truck engine. Especially in climates like the hot summers of Texas.
Thermostat Video Transcript
This is a thermostat out of an engine that controls the temperature of the coolant in the engine. In Texas, the engines tend to overheat and many times people put a thermostat that thins the engine. Put a thermostat in the engine that’s too hot. You can see the rating in this one is 195 degrees. Normally in Texas it should be a 160 thermostat. Be sure you have the correct thermostat in your car so that it doesn’t overheat in the hot summer.