A Powerful Single-cylinder Passenger Machine.
ONE of the best known names in the early days of motor cycles, the Quadrant remains a sound straight-forward machine that is a typically British production embodying good workmanship and solid useful design.
The latest addition to the Quadrant range is the new 6 h.p. single-cylinder outfit, which in all its main features closely resembles the better known 4½ h.p. model.
Having a single bore and stroke of 87 x 110 mm. respectively (653 c.c.), the design retains the well-known Quadrant disposition of the valves, the exhaust being at the side, and the inlet behind the cylinder. Special care has been taken to ensure an easy flow for both inlet and exhaust gases, and two features in this respect are obvious, though a full appreciation cannot be obtained without sectional drawings. The obvious features are the gradually expanding inlet pipe, and the very large expansion chamber for the exhaust gases. The silencer itself is of unusual construction, in that the end plates form part of the engine cradle castings, and hold between them a large diameter tubular expansion box, from which a tail pipe runs below the left footboard.
The Motor Cycle November 25th, 1920 Page 651
The 1920 Olympia Show.
Quadrant. (Stand 41.)
6 h.p.; 87x110 mm. (653 c.c.); single-cylinder four-stroke; side-by-side valves; hand pump lubrication; Amac or Senspray carburetter; gear-driven magneto; three-speed Sturmey-Archer gear; chain drive: 26x2½ in. tyres. Price with side-car £155.
March Newark and Co., Ltd., Lawley Street, Birmingham.
The Quadrant is a serviceable and steady mount, suitable for everyday hard work without needing undue care or attention. The principal model is the new 6 h.p., chiefly notable for a very wide and substantial crank case, which is kept smooth on the exterior, and, therefore, is exceptionally easy to clean. This idea has been consistently carried out, in that the number of plated parts on the motor cycle is reduced to a minimum. The riding position, and shape and length of handle-bar are good, and the sidecar chassis appears to be quite substantial enough to stand the exceptionally rough usage which this type of machine is usually accorded. Mechanically, the design differs from the ordinary in that the two valve ports are entirely separate, the inlet valve being behind the cylinder and the exhaust at the side, in a position where it obtains the maximum cooling draught. By this arrangement the valve springs, valve stems, and cotters become quite accessible, and can be cleaned or adjusted without trouble. A second model of 45 h.p., also a single-cylinder, is shown on the stand, and is designed chiefly for dual-purpose work.
To add to the interest, a sectional engine of this type is shown, and prospective customers can see for themselves every part of the mechanism, including the crank case, timing gear, and valve operation, while, as this engine is of the same design as the 6 h.p., the method of actuating the two valves by separate cams can be studied in detail. The smaller machine is sold with sidecar at the very moderate figure of £145.