Brits with SIX appeal

The straight-six engine is synonymous with a decades-long legacy of great British sports cars. Six variations on the sextet theme convene for comparison

- CHARLIE CALDERWOOD

Think American muscle car and you think V8. For the Italian supercar it's the V12, or for the Japanese 'tuner' generation the 2-litre turbo.

Certain types of car become synonymous with particular engine configurations they just fit the job so well. For Britain, and in particular sports cars, it's the straight-six.

As with all of those examples, it's a mixture of both engineering fact and more human concerns that have made six cylinders in a line the default choice. The uniquely British element of the story is the tax horsepower system, in effect until 1947, which penalised bore size (as in cylinder diameter) and encouraged long-stroke engines that produced healthy torque, but which didn't particularly like to rev. The era's poor-quality fuel encouraged that even further. If you want an undersquare engine to have a half-decent ability to rev, you need to make it as smooth and as well-balanced as possible which made an in-line 'six' ideal for the job.

The straight-six gives British sports cars a distinctive character: their engines major on torque rather than high-rev horsepower, making them perfect for pushing the car out of innumerable tight country bends rather than high-speed freeway, autobahn or autostrada use. Even after the tax horsepower system was binned, engineers who had grown up under the regime still bore excuse the pun - those sensibilities.

Today, it's hard to imagine one country producing so many similar yet unrelated engines, but in the six cars present here we have a selection of Britain's finest 'sixes', in some of the best cars to wield them.

JAGUAR XK150 & ASTON MARTIN DB5