Vintage Sports Car Illustrated Review: 1957 AC Ace – The Progenitor of the Cobra With An Engine Dating Back to 1919

Everyone knows that the legendary Shelby Cobra was of course an AC Ace with a massive dose of Ford V8 hormones. But probably fewer of us know much about the actual Ace, before that intervention by Carroll Shelby. This vintage SCI test was the first time I’d read anything of the kind, a comprehensive review of the Ace as it was in 1957 with its 2 L OHC inline AC six that dated all the way to back to 1919. Hard to believe, actually, given how much progress there was in engine design in the 40 some years it was in contiguous use.

It should be noted that as of 1956, the Ace was also available with a more potent Bristol 2 L six, a design based on the prewar BMW 328, but only some 20 years old instead of 40. And in 1961, there was also a version with a modified 2.6 L Ford Zephyr six. The Ace was an excellent chassis with a svelte bod apparently always on the lookout for a new engine. It found that soon enough.

I’m not going to do a full history of AC Cars, which dates back to 1901. But the key thread that leads to the Ace started in 1919-1920, with the AC 12 HP Tourer (above) and its superb new OHC six cylinder engine designed by John Weller, one of the two founding brothers. It was highly advanced for the times. It initially displaced 1447cc and made 40hp. In May 1924, at Montlhéry near Paris, T.G. Gillett broke the continuous 24-hour record in a 2-litre AC with special bodywork.

The Wellers lost control of the company during the Depression, but AC survived. Given the intrinsic sporting capabilities of the six, AC developed a line of sporting cars to maximize its potential, such as this beautiful one from 1937.

After the war, AC built the Two Liter as a sporty tourer, in both convertible and saloon body styles from 1947 to 1956.

The company desperately needed a new chassis and body to compete in the sports car boom of the 1950s, and found it in this roadster designed by John Tojeiro. The chassis was based on two main tubular frame members and independent suspension front and rear via upper transverse leaf springs and lower control arms. For 1953, it was quite advanced, especially the rear suspension. The lightweight aluminum body is undoubtedly inspired by the Ferrari Barchetta of 1949.

Here’s a better view of that 1919 engine, which used three SU carbs from day one. It has an aluminum block with wet cylinder liners and a cast iron hemi-head cylinder head. It really didn’t change very much at all in the ensuing decades, except that its performance steadily increased from 40 to some 100 hp. The 1957 version tested here was rated at 90 hp @4500 rpm. It was a classic undersquare British engine, with a 2.56″ bore and a massive 3.94″ stroke.

That may not sound like much, but it could keep up with a new Thunderbird V8 in acceleration up to 75 mph.


Acceleration (0-60 in 11.6 sec.) might seem a bit modest from our current POV but in 1957 this was right in the ball game with most of the better/quicker sports car, as we’ll see from upcoming reviews from this issue. Acceleration isn’t everything.


The Ace’s handling, steering and brakes were stellar, including on rough surfaces. This is what set it apart from the more primitive competition from Austin-Healey, Jaguar, and the like, including the Corvette. All suffered from their more primitive underpinnings, especially their leaf sprung solid rear axles.