AJS Porcupine World Champ
Against all odds, the British AJS factory won the very first 500cc World Championship. It was all downhill from there…
In contrast to 2019’s 19-round, nine-month marathon which concludes on 17th November, it took just 11 weeks to complete the inaugural FIM World Championship in 1949. Run over six rounds, points were awarded to the first five finishers in each of the four solo and one sidecar categories, with an extra point for the fastest lap of the race. While all results counted for the 125cc and 250cc championships, only the best three counted in the 350cc and 500cc classes.
On September 4th, 1949, ex-RAF pilot Les Graham DFC was officially declared Champion of the World in the premier 500cc class, despite crashing in the sixth and final round of the inaugural FIM World Championship. On the best-three-results system, Graham scored two wins and 31 points in the title chase, two more than Gilera’s Nello Pagani, who had grossed 40 points. In fact, Graham clinched the title at the penultimate round in Ulster, having achieved an unbeatable net points haul. AJS also took out the Manufacturer’s Championship in the 500cc class for 1949 by a single point from Gilera. Graham’s mount was the AJS E90 ‘Porcupine’ parallel twin, developed from a pre-war design originally intended to be supercharged. In fact, as far back as 1939, AMC engineer Harry Collier had designed a three-cylinder water-cooled supercharged racing engine, which never went beyond the blueprint stage due to the outbreak of war. Herein lies a little known Australian connection to the Porcupine. Phil Irving, the Australian engineer with lengthy stints at Vincent and Velocette on his CV, joined Associated Motor Cycles (owners of AJS and Matchless) in 1942, where he met up with his good friend Joe Craig, who had joined AMC after leaving BSA. Phil was shown a topsecret project code named E90S, the S standing for Supercharged, which Craig had taken over as project head, with a young draftsman named Vic Webb in charge of drawing. As well as other duties for wartime production, Irving also became part of the E90S development. Initially, a Roots-type supercharger was mounted above the gearbox but that aspect had to be abandoned when the post-war rules for GP racing, (and the new-for-1949 World Championship) were drawn up, supercharging was out, so AJS had to redesign the layout for conventional carburettor induction. E90S became E90. However the compromises were many, including the absence of flywheels, which was one factor that made the
E90 a beast to start, so much so that it often had to be towed behind a car to fire it up.
The ‘Porcupine’ gained its moniker from the peculiar spikey finning of the one-piece cylinder head. In a radical departure from usual British practice, the engine lay almost horizontal at 15 degrees, with a four-speed gearbox built in-unit. Three main bearings supported the crankshaft which was of 360 degree firing order, with bolted up aluminium rods. Primary drive was by gear, meaning the engine rotated backwards. A further departure from the usual AJS propensity for chain driven overhead camshafts was the use of a train of eight pinions to drive the twin camshafts running in a ‘Y’ shaped case on the right hand side. The cylinder finning was radial around the barrel to assist the passage of air. Gearbox was a special 4-speed Burman, with the final drive on the right – the opposite side to the clutch. Sitting across the top of the gearbox, a shaft drove the BTH Racing magneto and the twin oil supply pumps, with the return pump in the dry sump.
The frame was a very wide double cradle with the AMC Teledraulic front fork that had been developed for wartime use on the 350cc WD Matchless, with AMC-made rear suspension units on the swinging arm; typical of the quirks that beset AMC thinking at the time. Rather than buy proprietary shock absorbers from Girling or Armstrong, AMC insisted on using their own design – originally ‘Candlesticks’ and later the fat ‘Jampots’ – which were of poor design and even worse performance. Up front sat the 21 inch wheel that AMC still favoured for their racers, despite the
almost universal 19 inch wheels of rivals. Both of the magnesium brakes had twin leading shoes. Petrol tank capacity was six gallons (27.25 litres) although it looked bigger due to the large hollow underneath to direct cooling air onto the oil tank. The Porcupine made its ‘media’ debut in May 1947, then was given a quick squirt down the Rochester Bypass road before being whisked off to the Isle of Man where Les Graham and 39-year-old AMC Sales Manager Jock West (who had won the 1938 and 1939 Ulster Grands Prix on works BMWs) were entered for the Senior TT. Numerous teething troubles were encountered, including the clutch’s fabric-lined plates’ inability to handle the power, but Graham pushed home for ninth after his chain broke at Governors Bridge, just metres from the finish on the final lap, while West soldiered on to finish 14th. Both had experienced spark plug trouble due to the breaking down of the mica insulation then in common use for plugs, which led to Lodge developing the first ceramic-style plugs which were initially for the exclusive use of AJS. Towards the end of the season, Ted Frend scored the first win for a Porcupine in the 100-mile Hutchinson 100 at Dunholme Lodge Airfield in Lincolnshire.
West, Graham and new recruit Ted Frend all failed to finish the 1948 Senior TT, but in other races things were improving. West finished second in the Belgian GP at Spa and third in the Dutch TT at Assen, and Graham took third in the Ulster GP in Northern Ireland. With the instigation of the World Championships in 1949, AMC, AJS’s parent company, redoubled its efforts against the might of arch-rival Norton and the Italian Gilera factory. West stepped down from riding (apart from the Ulster GP) in order to manage the team, while Bill Doran was recruited to join Graham and Frend. The very first World Championship opened at the Isle of Man, and when the flag dropped for the start of the Senior race, things looked good for AJS. Graham and Frend tore off into the lead, easily out pacing the Nortons, but the three Porcupines were soon overhauled by Bob Foster’s Guzzi vee-twin. It became a two-way battle between Graham and Foster after Frend crashed, but with one lap to run Foster’s gearbox packed up, leaving Graham an apparent cruise to a popular win. Then came heartbreak as Graham sailed through Hilberry to the cheers of the thousands of fans, the howl of the Porcupine stopped. Whipping in the clutch, Graham was able to free-wheel up the hill to Signpost Corner, from where it was all downhill to the finish line. Before he could make it, nine other riders, including team mate Doran, had passed Graham as he pushed homeward, arriving exhausted to a hero’s reception.
As a result of the failure of the two-piece magneto shaft, which also put Rod Coleman out of the 1951 Italian GP, drive to the magneto was
eventually (in 1953) changed from gear to chain (and to a solid shaft rotating magnet style) in order to soften the effect of the firing impulses.
Two weeks later, Graham had his revenge, triumphing around the slippery, cobblestoned
Berne circuit to win the Swiss GP and gathering an extra point for setting the fastest lap of the race. The following week it was Pagani’s turn, taking the four-cylinder Gilera to a 3-second victory over Graham at Assen. Then at the ultra fast Spa-Francorchamps circuit, Doran won the Belgian GP when Graham retired with a leaking fuel tank. Crucially, Pagani could only finish fifth; a result that would cost him dear. A long break awaited the contestants before the Ulster GP over the Clady circuit near Belfast, but Graham won again, with local Artie
Bell (Norton) pushing Pagani back to third.
Graham’s race average of 96.49 mph (with a new record lap at 98.08 mph) made the Clady circuit the fastest in the world at the time. That result gave Graham the championship, and AJS the Manufacturers’ title, regardless of the result at the final round at Monza. For Graham, it was just as well. At Monza, he was leading the 500cc race with a phalanx of Italian machines behind him – three Gilera ‘fours’, three Gilera singles, three Moto Guzzi twins and seven singles – when he was rammed by Bandirola’s Gilera, putting both of them out of the race. Pagani took the win for Gilera to finish runner up in the 500cc Championship.
While AJS’s title win was the cause of rejoicing in the stoic British fashion, back in Gallarate Gilera were in no such high spirits. Within days of the Monza result, work had begun in earnest to go one better in 1950. Meanwhile, back in London, the AJS management was at loggerheads as to the future direction of their racing effort. Cash was short, export sales a priority, and despite the Championship, the E90 engine was far from perfect. The cylinder head in particular had been designed specifically for supercharging, and hence low compression, with the combustion chamber, wide included valve angles of 90 degrees and huge exhaust ports to suit forced induction. Without supercharging, these specifications robbed the engine of power and torque. The head, with its widely spaced magnesium cam boxes (due to the wide valve angle) and spikey fins was a nightmare to cast. A completely new head design was needed to combat not just Gilera, but Norton who were also smarting (and also strapped for cash), but there was little hope of getting such a costly modification through the AMC board. However designer Matt Wright did achieve a small benefit by reducing the valve included angle to 79 degrees and slightly modifying the combustion chamber.
As a result, AJS slipped from champions to alsorans in 1950 in the face of a resurgent Gilera, which won the title with Umberto Massetti riding, and the combination of the new Featherbed Nortons and the brilliance of Geoff Duke. Graham finished third behind Duke, scoring a single win at the Swiss GP, and despite an horrific crash at the Belgian Grand Prix. Graham was chasing leader Bandirola’s Gilera when the Italian braked unexpectedly for the fast Blanchimont corner and Graham clipped his rear wheel, sending him sprawling. Close behind, Norton rider Artie Bell had nowhere to go and also fell, the AJS and the Norton ending up under a timekeeper’s booth, destroying the Porcupine. Graham was uninjured but Bell’s left arm was shattered, ending his career. Even for the patriotic Graham, enough was enough, and he left to join MV Agusta for 1951, when things got even worse for AJS, despite the E90 engine being substantially redesigned, with separate cylinder heads and even conventional horizontal finning, plus a cast magnesium oil tank under the engine. Wheelbase was shortened, weight pared, and wheels standardised to 19 inch front and rear. The Porcupine appellation was no longer relevant but stuck nonetheless. Bill Doran’s second behind the untouchable Geoff Duke at the Isle of Man was the highlight of the season.
It was a case of convert or quit for AJS, and the London company decided to bite the bullet for 1952 with a heavily revised design, known as the E95, designed by Phil Walker, who had also designed the post-war 350cc 7R, and Ike Hatch. The engine was reconfigured to stand more upright at an angle of 45 degrees, with conventional fins between the cam boxes. The carbs were finally rubber-mounted to isolate them from the high frequency vibration that had been a problem from the beginning, and finally, the gear drive to the magneto was replaced by chain. Careful attention was paid to both inlet and exhaust porting, and the frame was redesigned in non-loop form and lowered to offer a better riding position. The conventional oil tank was discarded in favour of a cast magnesium wet sump, so pre-heated oil could be easily used to aid starting, which had always been a problem. Only one E95 was ready in time for the 1952 Isle of Man TT, ridden by New Zealander Rod Coleman.
Although no official figures were published, it is thought that the new engine was good for about 54 horsepower. It made little difference, as the engine continued to suffer from fuel starvation on high speed circuits, although the season began on a very high note with new signing Jack Brett heading home Doran for an AJS 1-2 at the Swiss GP which preceded the Isle of Man TT, where Rod Coleman came home in fourth place. AMC Racing Department head Matt Wright described the E95 redesign as “a complete waste of time”, and soon left AMC. Rod Coleman, who rode both versions, says the E90 was a better bike, and that both models were severely handicapped by AMC’s policy of strictly using products from its preferred suppliers: Amal, Lucas and KLG – all of which he claimed were inferior. Somehow, AMC found the funds to allow the E95 to continue for 1953 and 1954, with Jack Williams taking over the running of the race team in the latter year. The major modification to the 1954 E95 was the use of large ‘pannier’ fuel tanks (made by Ted Frend’s company Paramount Sheet Metal) and the use of an AC car-type fuel pump to transfer fuel to a header tank and thence to the carburettors. According to Rod Coleman, this completely cured the fuel starvation and carburation problems that had traditionally bugged the E90s and the earlier E95s. Results were still scarce, with Coleman finishing second at Ulster, only to have the results annulled when torrential rain forced the race to be stopped just short of the minimum distance of 200km. The New Zealander also won the non-championship Swedish Grand Prix. At season’s end, the AJS works team was disbanded, along with Norton’s, which by now was also owned by AMC.
The survivors
Only one of the E90 works bikes – the original Porcupines – still exists, in the hands of prolific Irish collector Sammy Miller, where it is displayed at his museum in New Milton, UK. Miller has demonstrated the unique machine on several occasions, including at the Pukekohe Festival in New Zealand in 2008. Despite displaying its noted cantankerous nature, many hands finally sorted the problems sufficiently to allow Miller to complete several laps of the circuit.
In contrast, all four of the later E95s are known to survive. Rod Coleman says “There were in all 12 Porcupine engines built; four in 1947, four in 1951 and the final four in 1953.” And while these differed externally, inside they were virtually identical, which Rod says explains why there were ‘empty’ E90 engines discovered, having been robbed of parts for the later units. After being mothballed for years, one of the 1954 E95s briefly returned to the track in 1964 (updated with Norton forks, Girling rear shocks and Fontana front brake), ridden by Canadian
Mike Duff and Londoner Dave Degens for owner Tom Arter, who acquired it from the AMC factory in 1964. That motorcycle was sold in 2000 at the annual Bonhams auction at the Stafford Show. The buyer was noted British collector and dealer George Beale who parted with £157,700 including buyer’s commission, which at the time was a record for a British motorcycle. It is now owned by the Barber Museum in USA. A spare E95 engine, also sold at the Stafford auction, went to Team Obsolete in New York and was used to complete their E95 which until then had contained a dummy engine with no internals, and had been purchased from the estate of the late John Griffith and had been displayed at the Stanford Hall Museum in Leicestershire for many years. That E95 has been used numerous times since for demonstrations and classic racing. In 2011, another E95, owned by the founder of the National Motorcycle Museum in Coventry, Roy Richards, was sold post-auction for US$675,000 after being passed in at Bonham’s ‘Quail Lodge’ auction at Pebble Beach in California.
The ‘Porcupine’ remains the only twin-cylinder engine to win GP racing’s premier title. With the shortcomings of the engine’s design due to the banning of supercharging, and the penurious state of the AMC concern, it’s remarkable that it raced at all, let alone win a World Championship. Chronic carburation issues made the original version tricky to ride, and AMC’s point blank refusal to allow streamlining to be used left it further disadvantaged. Yet the ‘Porc’ remains one of the most stunning looking racing motorcycles ever created, winner of five Grands Prix and one world title.