AC
Ace 2.6 'Ruddspeed'

Why it matters

The 2.6-litre 'Ruddspeed' Ace was the most powerful six-cylinder version of AC's sports roadster and the last step before the Cobra. Only 37 Aces were built with the tuned Ford Zephyr engine, and they shared seats, windscreen and much of the body with the early Cobras built alongside them.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Each kind of rarity is rated separately and never combined.

Photos

Exterior, interior and detail photos with their licences.

• AC Ace 2.6 'Ruddspeed' (Wikimedia Commons search)
  Photo: Mr.choppers · CC BY-SA 3.0
• AC Ace 2.6 'Ruddspeed' (Wikimedia Commons search)
  Photo: Mr.choppers · CC BY-SA 3.0
• AC Ace 2.6 'Ruddspeed' (Wikimedia Commons search)
  Photo: Mr.choppers · CC BY-SA 3.0

Production

Every figure says what it counts.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

Introduced in 1953, the Ace was later offered with Ford of England's 2.6-litre inline-six from the Zephyr and Zodiac, tuned with Ruddspeed equipment. In Stage 4 form, with a Raymond Mays cylinder head and three SU carburettors, the engine was rated at 170 bhp. The 2.6 cars were built at the same time as AC's early Cobras and received a smaller, redesigned grille; the body is otherwise close to the leaf-spring Cobra.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

Identification guide

How to tell an original from a replica or later conversion.

Genuine 2.6 cars carry RS-prefixed chassis numbers (the catalogued car is RS5030, number 30 of 37), a Ford 2,553 cc six with Ruddspeed equipment such as a Raymond Mays head and triple SU HD6 carburettors, a smaller redesigned grille without the 'moustache' line under the headlamps, and Cobra-type seats and windscreen.

Sources

Each number links to the exact facts it supports.

1. 1
   RM Sotheby's lot catalogue: 1963 AC Ace 2.6 Ruddspeed (Monterey 2021) Level B

   • 37 Aces built with the Ford Zephyr 2.6-litre six

   Accessed 2026-11-11
2. 2
   1954 AC Ace, Auction 2012 Level C RM Sotheby's

   • 2.6-liter pushrod overhead-valve inline-six from Ford of England
   • 2.6-liter (2,553 cc)
   • three SU HD6 carburetors
   • Stage 4 factory-rated at 170 brake horsepower at 5,500 rpm
   • 170 brake horsepower at 5,500 rpm
   • four-speed manual transmission
   • front and rear independent suspension with double wishbones
   • double wishbones and transverse rear leaf springs
   • four-wheel drum brakes
   • Wheelbase: 90 in.

   Accessed 2026-11-12