Carburetter flow bench equipment, discussing orifices, vacuum pumps, and separator tanks, with comparisons to Vauxhall's methods.
| Identifier | ExFiles\Box 122\4\ scan0172 | |
| Date | 30th June 1938 | |
| -2- used for accurate work in the States. Sharp edge orifices are simple to manufacture, published work has been done on them in this Country, and moreover, Zeniths, using this type of orifice obtain results comparative with Vauxhalls. CARBURETTER DEPRESSION. The Vauxhall flow Bench used a similar water manometer to the one proposed, and a single scale mercury manometer. Owing to the difficulty of cleaning the mercury reservoir, and the trouble with corrosion, it is proposed that a U tube be substituted for the latter. VACUUM PUMP. In defense of the choice of a Nash Hytor Pump, be it said that this is on the recommendation of Zeniths and Vauxhalls, both of whom find the pump satisfactory. SEPARATOR TANK. This tank containing baffles, situated below the carburetter tray and hood is designed to collect some of the petrol from the mixture. At best only the heavy ends of the fuel can be collected in this way. The lighter and more highly inflammable ends go to exhaust. This should be borne in mind, if the flow bench materialises when considering its location. (b) Notes on the use to which the flow Bench may be put, and to which it is put by Vauxhall's. In view of the high initial cost of a flow bench, considerable justification for the expense is required. In addition to their original flow bench, Vauxhall's now possess a second, less complete rig for use in production. Air flows are not measured, paraffin is used in place of petrol, the flowmeters are less expensive, and the mercury and water manometers for measuring carburetters depression are replaced by a single dog-leg mercury manometer, the lower portion of the scale being inclined for greater accuracy. No hood is placed over the carburetter, and for checking purposes the carburetter depression is taken to correspond to an estimated air flow, this being checked against flowmeter reading. Carburetters are checked in this way at four points on the part throttle curve and two on the full throttle curve. | ||
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).