IT is a fearsome-looking object, mostly engine which takes up all the room where a self-respecting machine would keep its tank, but this monster twin J.A.P. is fed from a small torpedo tank on the top tube; W. E. Cook, its intrepid rider, told us that he could certainly do three laps at Brooklands without running dry, but if he attempted four he generally had to walk up from the fork. The machine appears terrific in the garage, and what it looks like at over 90 miles per hour it is difficult to imagine. It has two cylinders, 120 mm. by 120 mm., set at 90 degrees, a 1½-l gear, and a carburetter which is large enough to contain many a light-weight engine.
The valves are overhead, M.O.V., just as on the 8 h.p. J.A.P.s. Auxiliary exhaust ports are cut in the cylinder walls, and these, combined with the double exhaust ports in the cylinder heads (which are detachable), should allow a free enough exit for the gases. C.A.V. coil and accumulator is a part of the ignition outfit. Cook said that, with fully-retarded ignition, the spark occurs dead on top of the stroke, and with a view to facilitate timing and tuning up of the cylinders, he has drilled and tapped two tiny holes in the cylinder heads so that a spoke can be inserted when the small plugs are unscrewed.
The lubrication is by drip feed, supplemented by a large oil pump on the top tube, this pump being worked from the left handlebar, which is also fitted with one of the two exhaust lifters, the other being situated on the right handlebar. The frame has been specially designed and made by the N.L.G. people, and is duplex throughout, and in some places, notably the head, the tubes are tripled. In spite of its enormous power, the machine did not strike us as particularly heavy, for we should estimate its weight at about 250 lb. Cook was persuaded, after considerable exertion on our part, to tell us some of his experiences with this projectile.
He thinks that 1½ to 1 is too big a gear, as the engine only really purrs with the wind behind it. so he proposes fitting a l 2/3-l instead. In spite of this terrific gear, he does not find starting a great difficulty; he runs the machine down a slope and, with a pusher-off to help, scrambles into the saddle when the engine fires. His chief trouble has been broken belts and pulleys, besides the innumerable times when the belt has flown off, owing to the excessive "punking" of the engine when turning slowly, for it does not begin to run sweetly until over 40 miles per hour is reached. To overcome the pulley difficulty, which also attacked him on his little 7 H.P. twin, he has constructed a pulley out of solid steel instead of cast iron, as formerly.
He says that the 16-20 h.p. does not keep the track well; in fact, he is hardly ever in the saddle when the speed gets up above 70 miles per hour. When travelling all out, the machine goes up the bank and cannot be kept within the 50-foot line, and this indicates what 90 an hour must be like when a machine has to automatically career up the Brooklands banking to get round a three-mile circle. A Longuemare carburetter, which has almost become unrecognizable under Cook's adjustments and additions, is fitted between the cylinders and supplies two long induction pipes, drilled with small holes for priming purposes. Two-and-a-half inch wired-on Rom tyres are fitted. A Shamrock Gloria belt of 11/8 in. diameter has been used, and it is protected from oil flying out of the exhaust ports in the cylinder wails by a large and homely-looking metal shield.
W. E. Cook is a cheerful soul, and keeps himself fit for his record attempts by riding a racing pedal tricycle at week-ends. Few people know that Cook is really a clever amateur artist, and we saw several neat little sketches in paint and pencil made on the back of cardboard advertisements. He is modest, and it was with difficulty we could persuade him to give us any account of his doings, but he let fall the pleasing information that should any customers of the North London Garage fail to pay their bills, it would be their fate to come out for a spin with him in a side-car hitched up to the 10-20 h.p.! This awful prospect will doubtless extract the long-delayed cheque.
We have attempted to convey to our readers on the first page of this issue an impression of Cook going "all out" at Brooklands on his racing monster. His head is protected by a special leather helmet strongly padded and coming well down over his ears, so that in the event of an accident this device should save his head to a certain extent. Other racing motorcyclists prefer the pneumatic helmet strengthened with sheets of steel, but it is more than likely, in our opinion at any rate, that if there ever is an accident, it will not make much difference whether a man wears a helmet or not. As a matter of fact, Cook had a pretty bad spill one day last summer, when practising on his smaller racing machine. Something happened to the back wheel, with the result that it came out of the frame and sent "Cookie," as his friends call him, flying along the track.
Twice, he says, he tried to get up. but found he was still rolling over and over, until at last he came to a standstill, badly shaken and bruised, but still alive. According to some reports, when he does go for the kilometre record, he will not try to beat the present speed of 87½ m.p.h. by too much, so that there will still he a sporting chance for some other fellow to make an attempt to improve on Cook's figures. We doubt, however, if there are very many people particularly keen to break records and possibly necks when the speed rises much above 90!
Cook is well known to the crowd at Brooklands, for he always appears in a flaming red sweater and brown corduroy breeches, which can easily be distinguished a long way off. He is depicted in our illustration in his usual racing trim, and all that is needed to complete the impression is to hear the deep roar of his engine as he comes into the railway straight after leaving the banking under the members' bridge. On the main line, near by, the fastest expresses seem to crawl when Cook gets going on the 10-20, for have we not seen him crouching low on his machine and hurtling through the air at 90 an hour?
Motor Cycling, 1909
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