Powell motorcycles were built by the Powell Brothers of the Cambrian Foundry, Wrexham, in North Wales from 1920 to 1925.
1920 The brothers entered the market with a middleweight machine designed for them by an engineer named Edward Alexander Burney. It was a useful and capable machine with a side-valve engine of 548cc, with outside flywheel. It appeared to be very similar to the Blackburne (Burney and Blackburne). The engine sloped forward 30 degrees and was easy to remove. It had a three-speed Sturmey-Archer gearbox and belt drive to the rear wheel.
1921 Although the machine had been announced the previous year, it was not until 1921 that it was produced in any great number.
1922 A new range of miniatures was launched, all with a choice of two-stroke engine of various makes, and transmission options of two-speed or three-speed. One model had a sheet-metal enclosure that covered all mechanical parts and provided leg-shields - this was known as the All-Weather.
1925 Only the miniatures were in production that year and the brothers then returned their foundry to the manufacture of more profitable goods.
The 4 h p. Powell with Outside Fly-wheel.
FOR some months past we have been in touch with the well-known firm of Powell Bros., Ltd., the Cambrian Iron Works, Wrexham, who have been quietly developing a new line of business which takes the form of a 4 h.p. motor cycle. They are by no means newcomers to the field of internal combustion engines, though it was not until after the war that they decided to enter the lists as producers of a motor cycle.
Having secured as designer Mr. E. A. Burney, whose name is already well known in connection with the Blackburne and Burney machine, it is perhaps hardly surprising to find that the new engine is fitted with a large outside flywheel, but here the resemblance between the two engines ends, for many new and distinctive features are incorporated in the new Powell engine. Mr. Burney, who became a despatch rider in August, 1914, and ended his war-time career in charge of a repair workshop, had many opportunities of studying motor cycles under the hardest possible services and, naturally, the results of his experience have been embodied in the new design.
The engine has a bore and stroke of 85 mm. and 96.5 mm. respectively (547.8 c.c.), and the cylinder is inclined forward at an angle of 30°. A detachable cylinder head is held down by four long studs, the cylinder itself being. separately attached by nuts at the base of these studs.
Sprocket Outside the Flywheel.
A one-piece hollow crankshaft is carried in very large Skefko ball bearings on either side, and the flywheel is fixed on to the shaft immediately outside the crank case. By using a short, large diameter hollow shaft torsional oscillation is minimised, and the primary drive is rendered extremely accessible by its position on the outside of the flywheel. A split big end (1 1/8in. diameter x 1½ in. long) is employed, and the patented method of lubrication for this part is most interesting. The leading face of each crank web is grooved, the groove becoming gradually deeper until it reaches the inside of the hollow crank pin, so that oil is flung into the pin by centrifugal force. It then reaches the bearing via a hole drilled radially in the crank pin, and is distributed over the surface by two grooves cut in the crank pin and forming an inclined angle of 50°. These grooves have a maximum depth at the hole and taper away to nothing, while there are no grooves in the bronze bearing. Half-inch diameter hollow adjustable tappets, working in cast iron guides, operate the side-by-side valves, and the arrangement of cam and distribution gear deserves special attention. A single cam controls the lift of both inlet and exhaust valves, while specially formed rockers are relied on to provide the necessary variation in periods. Meshing with the cam wheel is a large bronze intermediate wheel, which in turn drives a steel wheel on the magneto spindle.
Lubricating the Timing Gear.
The cam and rockers are provided with special means of lubrication, and the intermediate wheel bearing is lubricated by oil thrown, off the cam wheel, the gear teeth of the former being narrower by 1/8 in. than the latter to facilitate this arrangement. A hardened thrust plate locates the loose gear wheels, and a single cover plate encloses all the timing gear.
It will be gathered from the above that the magneto is carried on the crank case.
A special bracket is, in fact, cast on the base chamber behind the cylinder, and the magneto is held in position by a single large stud.
Two points immediately strike the observer. The engine is remarkably clean as regards oil leakage, and it has no awkward crevices or excrescences to collect mud, every corner being carefully rounded. Probably the disposition and arrangement of the large ball release valve has much to do with the fact that the engine keeps so clean.
Before passing on to the frame and transmission, one other important point must be mentioned. Owing to special construction, it is claimed that the engine unit complete with magneto and carburetter can be removed from the frame in ten minutes. This is largely due to the method of engine fixing, for the unit is carried by plates, permanently fixed to the frame and extending from front to back so as to form in effect a loop frame.
Transmission is by chain and belt through a Stnrmey-Archer three-speed gear. The frame has a slightly sloping top tube curved downwards at the rear, and a two-gallon petrol tank is fitted. Oil is pumped to the engine by a plain enclosed oil pump, and the frame details follow standard lines, though only the highest class of fittings are employed.
On the road a curious and desirable combination of effects is noticeable, for the engine combines the slow tick over and excellent pulling powers, which go with a large outside flywheel, with the freedom and "revving" qualities of the more usual inside flywheel type.
A very fair turn of speed is available in spite of the fact that the machine which we handled is the first, of its type, and remains unfinished in certain details, having fired for the first time a day or two before our trial.
It is expected that the new machine will be in production in time for the next Olympia Show, and we feel justified in prophesying a rosy future for such an admirably designed motor cycle.
The Motor Cycle August 12th, 1920. pp 203, 204
Serviceable Solo Two-stroke at a Moderate Price. Chain-driven 547 c.c. Model.
IT comes as a surprise to learn that the makers of the Powell are introducing a lightweight for next year. Hitherto, of course, there has only been one Powell model, a sturdy 547 c.c. dual-purpose mount, and this will be retained with the addition of a similar machine with all-chain transmission.
The lightweight is a straightforward and simple design, embodying a 247 c.c. Villiers engine, and, in two cases, a two-speed Albion gear box, in a neat frame not unlike the larger type in general contour. Single-geared, it is priced at £36, with plain two-speed at £42, and with two-speed, clutch, and kick-starter at £45.
Considerable reductions have been made in the prices of the 547 c.c. Powells, which are now : £87 10s. with final belt drive, £90 with final chain drive, and £110 chain-driven with sidecar.
The inclined engine, with outside fly-wheel, detachable cylinder head, and very complete lubrication system, is practically unaltered.
Powell Bros., Cambrian Iron Works, Wrexham, is the address of the makers.
The Motor Cycle November 16th, 1922.
The 1922 Olympia Show.
Two-stroke Models Introduced.
4 H.P. Model
85x96.5 mm, (547 c.c); single cyl. four-stroke; side valves; hand pump lubrication; Amac carb.; chain-driven mag.; 3-sp. gear clutch and kick-starter; chain-drive; 26x3in. tyres. Price: Solo, £ 90; with Sidecar, £110.
Powell Bros., Wrexham.
Of the three 547 c.c. Powell machines, one is a sports model with low handle-bars and a low saddle position. The second is a fully-equipped touring machine, and the third has a sidecar. All three are interesting by reason of the high finish, the exceptionally workmanlike way in which the accessories and details are carried out, and the fact that the single-cylinder engine is carried in an inclined position, instead of vertically as is usual. Inclined as it is, the cylinder gives more room in which to work on any part of the engine, and to a certain extent better cooling is obtained. In addition, this machine has now a really serviceable front wheel brake, and seems altogether to be the work of practical riders.
2½ H.P. Model.
67x70 mm. (247 c.c); single cyl. two-stroke: drip feed lubrication; B.&B. carb,; flywheel mag,; 2-sp. gear; clutch and kick-starter; chain and belt drive; 24x2¼in. tyres. Price £45.
A smaller model is a two-stroke on conventional lines and of very light weight. Care, however, has been taken to include everything which the rider may desire for the operation and control of the motor cycle. Mudguards of adequate width are fitted to protect the mechanism and the rider. There is also a 343 c.c. Villiers-engined model, which, with a three-speed gear, is suitable for light sidecar work.
Source: Graces Guide
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