Societá Italiana Auto Trasformazioni Accessori (SIATA) created a marvelous assortment of machinery in its 45-year history under the guidance of the Ambrosini family.

Founded by Giorgio Ambrosini in 1926, Siata specialized in performance modifications for Fiats, creating the overhead-valve conversions, multi-speed gearboxes, superchargers, and multi-carb intakes that competitive Italians wanted for their diminutive cars.

The Italian auto giant conspicuously ignored—with few exceptions—the high-performance market as the Agnellis concentrated their empire around sensible, reliable, and mass-produced cars of small proportions.

Siata received substantial financial assistance from Fiat following the Second World War, and by 1949 they were producing small automobiles which wore custom, house-labeled coachwork.

Firmly grafted to Fiat and its engineering, Siata took a giant leap forward with the arrival of Rudolf Hruska in 1950.

Hruska had worked in Porsche’s design office before the war a...