From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Brochure for the Orkan Type 'R' carburetor for motor-cycles, detailing its operation, fitting, and adjustment.
| Identifier | ExFiles\Box 122\4\ scan0040 | |
| Date | 11th September 1927 guessed | |
| ORKAN SCHEME OF THROTTLE WORKING running light, 1/4, 1/2, full load fig. 1, fig. 2, fig. 3, fig. 4 When the motor is running, the fuel is raised by the depression above the upper end of the descent tube, and after having been mixed with the air drawn through the air nozzle it flows down the descent tube, and enters the hollow throttle axle, where the mixture is divided into two parts according to the relative opening of the throttle. When the engine is running light (Fig. 1) the fuel is mixed a second time with the air entering through the ports of the throttle which open towards the air inlet, the twice atomized fuel passing through the restriction in the hollow axle and the opening a), and entering the suction tube as a delicate spray. At a little opening of the throttle (fig. 2) the mixture is divided into two parts, in the hollow axle. One branch continues providing the device for running light, the other branch passing through an opening in the walls of the axle, and entering the port of the throttle where the air passing at high speed atomizes it once more. The supply of fresh air has diminished, while the supply of mixture has increased, until. At the full opening of the throttle (fig. 4) all ports of the same are engaged by the depression of the motor and supply only a spray of fuel. ORKAN FITTING UP THE CARBURETOR 1. The „Orkan“ carburetor for motor-cycles is pushed on the end of the suction tube, so that the latter is fitted into the turned part of the throttle case, and pinched by means of the screw of the tightening device, so that the float chamber is placed on the top of the throttle case. 2. An efficacious filter is to be inserted into the fuel conduct; for that purpose we recommend our special fuel filter. 3. The fuel conduct should be as short as possible, the rotative float chamber may be suitably turned. 4. The gear or the Bowden wire for the operation of the throttle should have no lost motion, and give way to the full turn of the throttle. ADJUSTMENT The chief manoeuvre of the adjustment is the determination of the fuel-and air-nozzles, the former being found when the motor is running at maximum power. The air nozzle influences the consumption specially at high speeds, it must be selected, therefore, with regard to the motor working well at running light and in the transitions. The device for running light is adjusted by moving the crusted nut at the bottom of the throttle axle. When it is screwed off, the passage for the mixture which was choked before by the rod for running light becomes free, the mixture growing richer. The contrary effect is attained by screwing up the nut, the mixture growing poorer. As the device for running light continues working at all positions of the throttle, and as it depends on the sizes of the fuel nozzle and the air inlet, it must be had regard to when the carburetor is exactly adjusted. The motor is preferably started in the position for running light of the cold machine. By means of the diver the float may be depressed so as to flood the float chamber. »ORKAN« CARBURETOR TYPE „R” FOR MOTOR-CYCLES SUEDDEUTSCHE BREMSEN A.{Mr Adams}-G.{Mr Griffiths - Chief Accountant / Mr Gnapp} MUENCHEN 46 - GERMANY | ||