The Aceca (pronounced "A-See-Ka") is a closed coupé from the British AC Cars company, produced from 1954 until 1963. The car originally had an AC engine but the similar Bristol-engined Aceca-Bristol was also available alongside the original from 1956 to 1963 when production of the engine ceased. A few cars were built from 1961 to 1963 with a 2553 cc tuned Ford Zephyr engine and sold as the Aceca 2.6.
Based on the open two seat AC Ace, the Aceca was a hand-built grand tourer in the British tradition, with ash wood and steel tubing used in their construction. One notable feature was the hatchback at the rear, making the Aceca only the second car, after the 1953 Aston Martin DB2/4, to incorporate this element.
151 Acecas, 169 Aceca-Bristols and 8 Ford-engined models were built when production halted in 1963.
The main difference between the Aceca and Aceca-Bristol was the engine. Both used a straight-6 unit, but the Aceca shared its 90 hp (67 kW), 1,991 cc (121.5 cu in) overhead camshaft AC engine with the lighter AC Ace, while the Aceca-Bristol used a 125 hp (93 kW) "D-Type" 2.0 L (1971 cc/120 in³) unit sourced from Bristol Cars. The Aceca-Bristol was also available with a milder "B-Type" Bristol engine of 105 hp (78 kW). The Bristol specification added $1000 to the Aceca's $5,400 price tag in the United States. In the UK the basic car cost £1722.
The front-end styling of the Ace and Aceca reportedly traces back to a design done by Pinin Farina for AC in the late 1940s. The car is rather light owing to a tubular frame, aluminium engine block and aluminium body panels. Large 16" spoked road wheels, and near 50/50 weight distribution allowed exceptional handling on loose, dirt tracks. Later Acecas feature front-wheel disc brakes (added in 1957), while all share transverse "de Dion" leaf rear suspension, articulated rear half-axles, worm-gear steering, an optional overdrive on 2nd, 3rd & 4th gears, curved windshield, and leather covered bucket seats. The suspension is independent at the front and rear using transverse leaf springs.
The in-line six Bristol engine fitted to the Aceca-Bristol was based on a design from BMW with cast iron block and aluminium cylinder head. It has a single camshaft with pushrods running vertically to a rocker shaft on the inlet side of the engine and further horizontal pushrods running in 6 tubes over the top of the engine in order to reach the exhaust rockers. The two inclined rocker covers give the engine a similar appearance to an overhead - camshaft arrangement. Three inline Solex downdraft carburettors bolted directly to the cylinder head casting via small adaptor plates.
The car has a fairly hard ride owing to the stiff suspension and holds the road well in corners, with some oversteer. The narrow wheelbase is noticeable, though. On the downside, the 90 hp (67 kW) engine is best at higher rpm, so the 0-60 mph time is not exceptional. Other weaknesses include inadequate rear mirrors, even though the hatchback window affords a large rear view, a heating system that isn't suited for cold winters, and inadequate soundproofing for easy passenger conversation when cruising above 75 mph (121 km/h). The gear-shift is more solid than smooth and has synchromesh on 2nd, 3rd and 4th gears, only.