1957 AC Ace-Bristol Roadster
The Ace’s design traced back to a successful 1952 sports-racer built by chassis engineer John Tojeiro for Cliff Davis. AC Cars acquired the rights and launched production in 1954, retaining the Ferrari 166-inspired barchetta bodywork and Tojeiro’s twin-tube ladder frame chassis with Cooper-influenced all-independent suspension.
Bristol engine versions, introduced in late 1955, featured a 1,971cc inline-six based on the pre-war BMW 328. It incorporated hemispherical combustion chambers and inclined valves without the need for overhead camshafts.
The clever design used a single block-mounted camshaft with two rocker shafts, creating an appearance similar to a twin-cam layout. Up to 130bhp was available in road trim, allowing the Ace-Bristol to reach about 120mph, while racing versions extracted roughly 150bhp.
The combination of fine handling and a favorable power-to-weight ratio led to numerous racing successes, including a class victory and seventh overall at the 1959 Le Mans 24 Hours.
Production continued until 1963, with later examples also available with the 2.6-liter Ford Zephyr inline-six, and the design’s inherent strength later enabled its transformation into the legendary Cobra.
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