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).
Testing three different schemes for using a starting carburetter as a primer for the fuel pump and pipe line.
| Identifier | ExFiles\Box 27a\2\ Scan146 | |
| Date | 20th April 1933 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Std. c. By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}/Std.19/KT.20.4.33. REPORT ON SCHEME FOR USING STARTING CARBURETTER AS PRIMER FOR FUEL PUMP & PIPE LINE. Three separate schemes for attaining the above object were tried out :- (1) Starter carburetter was coupled to main pipe line from pump to carburetter. (2) Starter carburetter was coupled up to pump between suction and release valves. (3) Starter carburetter was coupled to main pipe line from tank to pump, very close to pump (actually in pump casting). The tests consisted of running the engine until it stopped - having sucked floatchamber, pump, pipe line and filter dry - running on self starter until engine fired, the time necessary being recorded, and running on starter carburetter until there was sufficient petrol in floatchamber to open up throttle - the time which elapsed to reach this condition being also recorded. Note. Pipe line of approx. the same length as used in car was fitted, also standard filter - the level of the tank relative to the engine being arranged to be approx. the same as in car. -------- Results. (1) With this arrangement it was found that suction from starting carb. gave no assistance to pump, as air was drawn back through floatchamber needle valve. Hence, without some form of non-return valve between floatchamber and starting carb. connection, this arrangement is useless. (Even if non-return valve were fitted the starting carb. would have to suck through pump, and lift both valves, a feat which judging by its performance in the next tests, it would be quite incapable). | ||