Last of its Species: 1947 AJS 500 E90 Porcupine

Alan Cathcart rides the last remaining AJS 500 E90 Porcupine racer.

  • AJS
    Sammy Miller's 1947 AJS 500cc E90 Porcupine.
    Photo by Kyoichi Nakamura

  • AJS

1947 AJS 500 E90 Porcupine
Engine: 498cc air-cooled DOHC parallel twin, 54mm by 54.5mm bore and stroke, 9:1 compression ratio, 48hp @ 7,600rpm
Top speed: 135mph (1949 Isle of Man TT)
Carburetion: Two 1-1/8in (28.5mm) Amal GP
Transmission: 4-speed, chain final drive
Electrics: Lucas magneto ignition
Frame/wheelbase: Dual downtube steel cradle/56.5in (1,435mm)
Suspension: AMC Teledraulic telescopic forks front, swingarm with dual AMC Jampot shocks rear
Brakes: 8.25in (210mm) TLS drum front, 8.25in (210mm) SLS drum rear
Tires: 3 x 21in front, 3.25 x 19in rear
Weight (dry): 335lb (152kg)
Fuel capacity: 6.5gal (24.6ltr)

Sammy Miller's passion for motorcycles, which led him to achieve success on two wheels in both trials and road racing before assembling one of the world's finest bike collections, started in Northern Ireland in the post-World War II era.

"My first impressions of anything to do with bike racing were in 1947," recalls Sammy, now an energetic and enthusiastic 83 years young. "That's when some of my pals and I rode our bicycles up to the Clady circuit for the first night of practice for the Ulster GP, on the Thursday evening. There we were in the hedge, on the Seven Mile Straight running down to Clady Corner — and the first three bikes that roared past us were the three AJS Porcupines, ridden by Jock West, Ted Frend and Les Graham, all on full rattle. It was unbelievably thrilling — and that was me sold on bikes for life, from that moment on!"

In the late 1970s, three decades and a thousand Trials victories later, the chance came to acquire not only one of those very same Porcupines that had so impressed him as a kid, but also the sole surviving example of its predecessor, the prewar supercharged V4 500cc AJS, from former AMC sales director and ex-works racer, the late Jock West. The fact they were both static displays without any engine internals was merely an additional challenge for someone like Sammy, who believes more than most that what man has made once, man can make again.

The restored V4 had already proved a star attraction at major European historic events, before being joined on the racetrack in May 2004 by the newly rebuilt "Porc." Together, the two ex-works AJS multis have successfully publicized the magnificent Sammy Miller Museum at New Milton, Hampshire, U.K. arguably Europe's finest and most extensive collection of fully restored historic motorcycles.

Riding the E90 Porcupine on the test track he's created on the grounds of Bashley Manor, where the museum is located, was a unique chance to sample the first-ever 500cc World Champion Grand Prix racer in action.
3/2/2018 11:20:53 PM

The bore and stroke you list for the '47 AJS 500 Porcupine twin cyl. engine (54.0mm b x 54.5mm s) are incorrect; this results in a piston displacement of 124.8 cc per cylinder, which would result in a 250-class twin vice 500cc twin.

3/1/2018 7:27:41 AM

Visiting the Sammy Miller Museum is something that every motorcycling enthusiast should do... It is in the same terms as Barber Museum... "Incredible".. Just different... so many of the bikes there were ridden by Sammy, including the most famous Trialer ever... Gov 132 Ariel 500 single; Multi- times winner of the "Scottish 6 Days" under Mr. Miller before the first 2T win in the early 60's. Located in a beautiful part of south central England just a few miles from the coast. Plan a visit on the way to the I.O.M. You won't regret it.

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