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).
Graph showing full throttle metering for a large S.U. carburettor with different needles.
| Identifier | ExFiles\Box 31\4\ Scan077 | |
| Date | 10th September 1931 guessed | |
| FULL THROTTLE METERING "CHINA" LARGE S.U. CARB. Pts/BHP/HR R.P.M NEEDLE W.O.3 NEEDLE 6Q W.O.2 | ||