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).
Tests conducted on the 'SS' expanding carburetter, detailing induction pipe depression measurements on a Phantom engine.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan083 | |
| Date | 28th January 1929 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. Hs{Lord Ernest Hives - Chair}/ACL2/LG28.1.29. c. to BJ. SG.{Arthur F. Sidgreaves - MD} c. to WoF. E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} ORIGINAL X7080 x7070 'SS{S. Smith}' EXPANDING CARBURETTER. We have had the opportunity of carrying out some more tests on the expanding SS.{S. Smith} carburetter. We regret the development of this carburetter has been retarded due to the more urgent work on the SS.{S. Smith} engine but have endeavoured to carry out tests with this carburetter on a Phantom engine where possible. Our previous tests shewed that the induction pipe depression was much too high - being 5.7" Hg. at 2500 r.p.m. full throttle - which we attributed to the area past the restrictor at full lift being too small. It will be remembered our first tests were to prove the power capacity of the carb. Continuing these experiments on a Phantom engine we made a test of the power and depressions with the restrictor held rigidly at various portions of its lift. It was so arranged that the restrictor could be withdrawn to 1.4 from its closed position, or .4 more than its original travel. These results are shewn on appended curves which were conducted at 2500 r.p.m. at full throttle. The curves of depressions are plotted against area past the restrictor, as this is withdrawn from the choke and it will be seen that the depressions progressively w- fall as the area increases but the fall of depression is at a slower rate as the restrictor approaches the extreme travel. Even when contd :- | ||