350 manx norton

We might add that the two machines were run "as delivered" and though they are sold as pure racing machines, much tuning and preparing is left up to the purchaser. This is especially true in the gearing as neither bike was properly geared for the track conditions of Riverside Raceway.

As a design, the Norton is remarkable mostly for being strong. The magnesium-alloy crankcase is very deep, and heavily ribbed to provide strength and a measure of cooling. A massive crankshaft assembly, with larger-than-. On the timing end of the shaft, a set of bevel gears take the drive into a vertical tower shaft, and from there it goes to another set of bevel gears and into the five gear drive to the two camshafts.

In the cam drive system, many adjustments are provided for setting the valve timing. In the "production" engine, and indeed in all those currently being raced, the valves are opened by short bucket-type tappets with radiused faces and closed by hair-pin valve springs.

This system works fine, and there is no problem with the valve float at any speed the engine's lower end will stand. However, on one side of the experimental short-stroke engines, the valves were opened and closed positively, without any springs. The opening was taken care of in a fairly normal manner, but additional cams were fitted on the cam drive's idler gears and short rockers leading from these were used to pull the valves shut.

With this layout there is no such thing as valve float, and it offers almost complete freedom in choosing valve timing. It is possible to bang the valves open and shut at a ferocious rate.

Unfortunately, a snag developed: the reflected inertia of the valves was causing heavy loadings on the rest of the drive, and there were failures of the couplings in the tower shaft. Finally, the less expensive and more reliable spring closing was reverted to, and that is where matters stand today. You might be interested to know that the Norton engine is thought of rather highly even outside the ranks of motorcycle enthusiasts. Not a Norton engine exactly; Vandervel used four of them.

After a series of tests on a watercooled version of the Norton Manx engine which would, as it turned out, deliver a bit more power than the aircooled original , a four-cylinder engine was built with valves, valve gear, cam timing, pistons and porting from the Norton. It was, as one might imagine, a tremendous success.

The car was afflicted with a variety of ailments and it was some time before it won any important races, but Vandervel's bundle-of-Nortons engine was outstanding for its power and reliability. The servicing of racing machines can present some problems — especially when special tools are required. The Norton does not present this kind of problem. Procedures for dismantling and assembly are uncomplicated, and a minimum of tools of any kind are needed for even the most extensive repair work.

Neither is there any need for special tuning or hand-finishing of the engine after purchase. Each of these engines is hand-built at the factory and checked on a dynamometer for output — and then stripped down, inspected for flaws, and reassembled before being sent out to the buyer. Engine tuners who specialize in re-working the Manx engine can get a bit more than is delivered as stock.

In England there are men like the famous Francis Beart, who with the help of the Norton factory turns out engines for the continental aces that are substantially more powerful than those being sold over the counter. However, these engines usually have too narrow a power band to be as versatile as those direct from Norton.

The machine offers a bronze skull in the cylinder head and is fitted with inch wheel rims as it became impossible to source tyres for the original inch rims. The carburettor has also been changed from the original remote needle TT to the easier-to-tune TT9 model; the original carburettor is with the machine. Soldered on the underside of the fuel tank are the scrutineering tags from the Manx Grand Prix, the first to be held after the war.

The left-hand side has 94 over meaning entry 94 in the cc race or Junior as it was known then. The engine and frame numbers are matching B10M This Norton 40M Manx is the real deal. The Manx is fully restored with an engine tuned and rebuilt by the legendary Ray Petty, and it includes a remarkable aluminum dustbin fairing, which adds tremendously to its cool factor.

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Meanwhile the racing department of the company continued to modernize the official models, which were transformed rapidly in those years to meet the tough competition provided by the motorcycles and racers of Rudge, Velocette, and Sunbeam in Britain, and Bianchi, Guzzi, and Moto-sacoche on the Continent. Between and the bore and stroke of the Grand Prix were changed twice and a double overhead camshaft distribution was installed for the first time. No other single-cylinder engine of that class could generate more horsepower, but its power was not enough to discourage the Italian and German makers of multi-cylinder models.

Norton managed to hold its own, especially on mixed circuits, where its weight-power ratio helped racers. The Norton company was fortunate to have such fine racers as Jimmy Guthrie and Harold Daniell, two of the greatest champions of the time, and new racers were continually appearing on the scene.

The first Norton motorcycles to reappear in racing in were old models that had been jealously guarded by their owners. Indeed, with the prohibition of superchargers it almost looked as if the single-cylinder might rule the roost, or at least have a temporary advantage over the four-cylinder Gilera, the two-cylinder BMW, and the two-stroke DKW. In reality, after losing the world championship to the two-cylinder AJS Porcupine in the class and to the single-cylinder Velocette in the class, Norton had to struggle in the following years to defend the slight margin that its racers had succeeded in winning for it.

From on, the chief factor in Norton wins was its innovative Featherbed chassis, which was designed for Norton by the McCandless brothers. With this chassis Norton could outrace any motorcycle of equal power, especially on difficult tracks. The Norton Grand Prix won the world championship in class , and , and These were not easy wins, and much credit was due to the fantastic skill of Geoffrey Duke, for whom the single-cylinder was perfectly suited.