1956 AC Ace

The AC Ace and its Cobra derivative have origins that trace back to a one-off sports-racer built by chassis engineer John Tojeiro for Cliff Davis in 1952. Its success prompted AC Cars to acquire the rights to the design, and in 1954, the Ace entered production.

The AC Ace retained the Tojeiro's Ferrari 166-inspired Barchetta coachwork, along with its twin-tube ladder frame chassis and Cooper-influenced all-independent suspension. Beneath the bonnet (hood) was AC's own venerable, 2.0-liter long-stroke six-cylinder engine. The originals of the overhead-camshaft engine date to 1919, and its design was by AC co-founder John Weller. In the Ace, the powerplant delivered great success in productin sports car racing.

Production of the Ace was exclusive, beginning in 1953 and continuing to 1963, with a total output of around 723 units. Approximately 223 examples were delivered with the 2.0-liter AC engine, 463 (as many as 466) with the Bristol engine, and an additional 37 with Ford power.

Mechanical Specifications
The AC Ace had a 90-inch wheelbase, an overall length of 152 inches, a height of 49 inches, and a width of 59.5 inches. The ladder-type tubular frame was comprised of small-diameter steel tubes in a variation of Touring's Superleggera techniques. It was suspended by an all-independent setup with transverse leaf springs, earning the Ace the distinction of being the first post-war British sports car with a fully independent suspension. Braking was initially via drums, with front disc brakes becoming optional from 1957, and was later standardized (Girling hydraulic brakes with finned aluminum ('Al fin') Wellworthy drum brakes). Wheels were 16-inch Dunlop knock-off wire-spoke units mounting 5.50-inch tires.

2.0 Liter I6 AC Engine
The two-liter (1991cc) overhead cam straight-six engine produced approximately 100 horsepower and endowed the lightweight sportscar with a top speed of 103 mph and zero to sixty mph in 11.4 seconds.

2.0 Liter I6 Bristol Engine
In 1955, the AC was joined by a hardtop version known as the fastback-styled Aceca. Both the Ace and the Aceca became available from 1956 with a more potent Bristol six-cylinder engine. The 1,971cc (2-liter) Bristol straight-six was based on the engine that powered the pre-war BMW 328. It featured a cylinder head designed by Rudolf Schleicher, incorporating hemispherical combustion chambers and inclined valves without recourse to overhead. It used the BMW Type 319 engine's single block-mounted camshaft and pushrod valve actuation which alleviated the expense of a redesign. Two rocker shafts were employed, one located above each bank of valves, giving the engine an external appearance almost indistinguishable from that of a twin-overhead-cam design.

The Bristol engine was taller and heavier than AC's own engine, but it was considerably more powerful thanks to its superior cylinder head design and down-draught carburetors. In road-going guise, the engine was tuneable up to 130 bhp, while racing versions tweaked out upwards of 150 bhp. Along with more power, the Bristol-engine Ace was also considerably more expensive, costing nearly 25% more than the AC-engine version. This put the AC Ace in the territory of the Jaguar XK140 (or two MGAs).

The transmission was a four-speed manual unit; overdrive became available from 1956.

2.6 Liter I6 Ford
In 1961, Ken Rudd offered a 2.6-liter straight-six engine known as the 'Ruddspeed'. Originally powering the Ford Zephyr, the 2.6-liter engine was tuned by Rudd with three Weber or SU carburetors and either a 'Mays' or an iron cast head. Output varied but could achieve upwards of 170 bhp, endowing the AC Ace with a top speed of 130 mph. A distinguishable feature of the Ruddspeed-powered Ace were a smaller grille, which was later adopted by the Cobra.

Coachwork

The lightweight alloy open two-seater coachwork of the ACE was hand-formed using English wheeling machines.

Motorsport Compecition
The AC Ace raced at the 24 Hours of LeMans in 1957, 1958 and 1959. Ted Whiteaway and John Turner drove an AC Ace Bristol (registration 650BPK) to a seventh-place finish and first in the 2,000 GT class at the 1959 Le Mans. The Ace placed second in class in 1957 and 1958.

In the United States, the ACE won three successive SCCA E-Production championships between 1957 and 1959, followed by two D-Production championships in 1960 and 1961.

by Daniel Vaughan | Jan 2025