Ported Vacuum Switches
A ported vacuum is a vacuum like the carburetor where the throttle has a vacuum above it that helps it function. It assists in timing and it has an opening that can be opened or closed to initiate or shut off the vacuum. The ported vacuum switch is a valve that stops up the passage of a ported vacuum. The vacuum is used to operate a mechanism. In the case of the throttle, the vacuum actually opens and closes the throttle in the carburetor. Ported vacuum switches can be operated by electrical signal or a mechanical component, or thermostatically. Ported vacuum switches are used in many applications like the carburetor, distributor, or the coolant system. In the coolant system, thermostatic ported vacuum switches are the most common. They function when there is a change in the temperature of the coolant. Distributors and carburetors use electrical ported vacuum switches.