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).
The testing of production and experimental carburettors for the Wraith model, detailing performance issues and proposed modifications.
| Identifier | ExFiles\Box 7\4\ X 608 Carburetter-page31 | |
| Date | 9th June 1938 | |
| 608 To By.{R.W. Bailey - Chief Engineer} c. to Is. c. to Mx.{John H Maddocks - Chief Proving Officer} c. to Rm{William Robotham - Chief Engineer}/Twdl. c. to Rm{William Robotham - Chief Engineer}/Sym. Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}10/JDL.9.6.38. WRAITH CARBURETTERS. Four carburetters taken from the first batch of ten received by production were tested for power and consumption on the test bed. These were tested in conjunction with two experimental models on the same engine with air and exhaust silencers complete. The two experimental models had been tested on the road for side by side acceleration with the result that one was better than the other particularly at 10 to 40 m.p.h. An increase in jet size made no appreciable difference to the bad carburetter on the road. A slight improvement was recorded on the test bed by fitting a .036 bypass jet, but does not account for the greater difference on the road. This carburetter will be tested again with the .036 bypass jet and an increased pump stroke in an effort to bring it to a more reasonable performance. This modification of the bypass jet was tried out on the four production carburetters in order to cater for full throttle variations and is included in the specification to the makers. Figures obtained on the test bed are attached. Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe} | ||