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).
Preliminary test report on the expanding throat carburetter fitted to the 'SS' engine.
| Identifier | WestWitteringFiles\T\November1928\ Scan011 | |
| Date | 1st November 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c.c. to BJ. Wo r.{Sir Henry Royce} c.c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c.c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LGS.11.28. RR. EXPANDING THROAT CARBURETTER. +7080 We have carried out some preliminary tests with the RR. expanding throat carburetter fitted to the 'SS{S. Smith}' engine. For these first tests we have concerned ourselves only with the power output the object being to determine if the carburetter choke area was adequate to permit development of maximum power or equal that power obtained with the RRCH. carb. which we have used for the previous tests and which results we hoped to reproduce with the expanding carburetter. We had difficulty in getting the mixture strong enough at full throttle but overcame this by fitting a jet needle with a steeper taper which we adjusted by hand. A full throttle power curve was taken together with the induction pipe depressions and these are shewn on appended print compared with the standard carburetter and the RRCH. carb. The induction pipe depression is considerably higher than desired which accounts for the low power output. It was desired to work with the same depression at the speed of maximum power as given by the RRCH. carb. This was 2.3 ins. of mercury at 2750 r.p.m. It will be remembered we supplied a report on some tests made on the Phantom which dealt with choke sizes and induction pipe depression which gave good power output - see report Hs{Lord Ernest Hives - Chair}/ACL/LGS.11.27 and 25.4.28. From these tests we found contd :- | ||