CTCI Authenticity Chairman
Pictured is a Mallory centrifugal advance tach drive distributor for a 1955 thru 1957 Thunderbird. It is identical to the vacuum controlled distributor except for the lack of the vacuum components. The vacuum chamber is blocked with a plate held with two screws. This type Mallory operates very well on the street with centrifugal advance only.
The vacuum portion of the Mallory distributor consisted of three parts. 1- A piston which acted as a brake to prevent timing advance. 2- A spring which held the piston against a disk that was a part of the centrifugal weight system. 3- A cover with gasket and vacuum tube.
Pictured is a Mallory, vacuum controlled,centrifugal advance tach drive distributor for a 55 thru 57 Thunderbird. The vacuum source from the carburetor works against a calibrated spring to pull a piston away from a disk attached under the centrifugal weights, allowing the distributor to advance. It was intended to provide a smoother operation of the advance curve for street use.