The success of Cliff Davis' Tojeiro sports-racer prompted AC Cars to put the design into production in 1954 as the Ace. The Davis car's pretty Ferrari 166-inspired barchetta bodywork was retained, as was John Tojeiro's twin-tube ladder frame chassis and Cooper-influenced all-independent suspension, but the power unit was AC's own venerable, 2.0-litre, long-stroke six. This overhead-camshaft engine originated in 1919 and with a modest 80bhp (later 100bhp) on tap, endowed the Ace with respectable, if not outstanding, performance. A hardtop version - the fastback-styled Aceca coupé - debuted at the Earls Court Motor Show in 1954. The Aceca's hatchback body was constructed in hand-formed aluminium over a tubular steel framework, while the tubular chassis was more substantially built than the Ace's. To reduce noise levels within the cabin, AC mounted all major components on rubber bushes. The result was a well-engineered, light in weight and extremely pretty GT car in the best AC tradition. Very few alterations were made to the Aceca during its production life apart from a change of engines. For the 1956 season the more-powerful (up to 130bhp) Bristol six-cylinder engine became available. The l,971cc Bristol six was based on that of the pre-war BMW 328, which featured an ingenious cylinder head, designed by Rudolf Schleicher, incorporating hemispherical combustion chambers and inclined valves without recourse to overhead, or twin camshafts. Instead, the earlier BMW Type 319 engine's single block-mounted camshaft and pushrod valve actuation were retained, thus avoiding an expensive redesign. Two rocker shafts were employed, one situated above each bank of valves, giving the engine an external appearance almost indistinguishable from that of a twin-overhead-cam design. Downdraught inlet ports contributed to the motor's deep breathing, and its tune-ability made it a popular choice for British racing car constructors, most notably Cooper, during the 1950s. Externally, Bristol's clone of the BMW motor differed little from the German original, the most obvious difference being the adoption of SU, rather than Solex, carburettors part way through production. The most significant changes made by the Bristol designers were metallurgical; their utilisation of the highest quality materials contributing to greatly increased engine life. The combination of a fine-handling chassis and a decent power-to-weight ratio - in Bristol-engined form the car could touch 120mph - helped the Ace to numerous successes in production sports car racing, arguably its finest achievement being a 1st-in-class and 7th overall finish at Le Mans in 1959. First registered on 16th December 1959, the matching numbers Aceca offered here was first owned by one Nicholas Vincent Paravicini while details of all subsequent owners on both sides of the Atlantic are contained within the accompanying history file. Chassis number 'BE762' retains its original Bristol engine (number '100D 1055'), front disc brakes and overdrive-equipped gearbox. Upgrades include alternator powered electrics, an electric cooling fan, the preferred Ben Yates rack-and-pinion steering, twin air horns and 15" wire wheels for superior handling and better tyre availability (the five original 16" wheels and tyres are included in the sale). Possibly raced in its early days, the always right-hand drive car went to the USA in 1969, where it was issued with Connecticut 'ACECA 1' licence plates before returning to the UK in 1997. In 1998 Plus 4 Motors sold the Aceca to Robert Mills, who prepared the car for light historic rally work, equipping it with large Monza-style filler cap, full harness belts, map light, twin air-horns and fire extinguisher. In this form, 'XGT 517' also took part in a Liège-Rome-Liège retrospective. Owned by the current vendor since 2003 and used for European tours without bumpers by choice (the originals are included separately however), the Aceca benefits from adjustable Spax rear shock absorbers, a new water pump and an invoiced engine top-end overhaul carried out by the respected motor engineers at Blakeney Motorsport earlier this year. Described as in generally sound condition, with excellent engine, red paintwork generally good, and largely original and acceptably patinated red leather interior, 'XGT 517' is offered with its original buff logbook, sundry invoices, FIVA Identity Card, only recently expired MoT/tax (July 2012) and Swansea V5C registration document.