AC Ace Variants: Ace, Ace-Bristol and Ace 2.6

Every AC Ace shares John Tojeiro's large-diameter tubular-steel ladder frame, all-independent transverse-leaf suspension and hand-formed aluminium panelling over a composite framework of steel tube and ash timber. What separates the variants is what sits under the bonnet, and that changes the character, the performance and, above all, the price. The same three engines were offered in the closed Aceca, so the comparison below maps almost exactly onto the coupé.

The three at a glance

Figures are period and published-history approximations. These were hand-built cars and sources disagree; verify anything critical against the Workshop Manual, the AC Owners' Club or the car's own records.

Ace (AC Light Six), the original

The car AC launched in 1953 used the firm's own Light Six, a single-overhead-cam alloy-block two-litre whose design dated back to John Weller's work in 1919. It is a wet-linered, long-stroke engine that rewards mechanical sympathy: unstressed, characterful and extremely long-lived when serviced properly, but never truly quick. Roughly 85 to 105 bhp depending on tune gave a 1954 Ace about 103 mph. For an owner who wants the earliest, purest expression of the car, and the lowest entry price of the three. This is the one.

Ace-Bristol, the one the market wants

From 1956 AC offered Bristol's 100D2, the BMW 328-derived cross-pushrod six with three downdraught Solex carburettors and up to around 125 bhp. It transformed the car: over 110 mph, far stronger mid-range, and a competition record that included two-litre GT class honours at Le Mans and dominance in American SCCA racing. About 460 of the roughly 720 Aces built were Bristol-engined, and it remains the variant most buyers chase. Servicing is more demanding, the cross-pushrod valvegear and triple Solex set-up both need specialist knowledge.

Ace 2.6, the rarest, and the Cobra's cue

When Bristol wound down engine supply in 1961, AC turned to the Ford Zephyr 2.6-litre six tuned by Ken Rudd, in stages quoted up to about 170 bhp and around 130 mph. Only 37 Aces were built this way, most wearing the lower, narrower nose that fed straight into the AC Cobra's styling. Rarity and the Cobra connection make genuine 2.6 cars the hardest of all to find, and the ones where verifying authenticity matters most, because rebodied or re-engined cars circulate. The same engine went into a small number of Aceca 2.6 coupés, rarer still.

Which should you buy?

If you want the competition pedigree, the strongest resale and the best two-litre driving experience, the Ace-Bristol is the default answer, and is priced accordingly. If you want the marque's own engineering and a slightly gentler ownership proposition, the AC-engined car is the better value and, to some eyes, the more authentically "AC" of the three. The 2.6 is a collector's car first and a driver's car second, simply because so few exist. The Ace values page sets out what each has actually been selling for, and Ace vs Aceca covers the open-versus-closed decision.

Frequently asked questions