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).
List of modifications for the Phantom twin-choke carburetter.
| Identifier | ExFiles\Box 13\3\ 03-page278 | |
| Date | 26th February 1931 guessed | |
| (1) The following are a list of Modifications up to date on the Phantom twin-choke carburetter Leo. 2810, 2811, 2812 & 2813. (1) Variable valve sleeves to V.1059 now having 3 - .066 dia. holes. (2) Diffuser body to V.1057 reduction in diameter from .498 to .475. (3) Diffuser outer tube to V.1060 bleed holes (top row) increased in diameter from .046 to .055 diameter. (4) Main chokes to V.1022 increased in diameter from 1.250" to 1.300 diameter. (5) Throttle spindle to V.1032 having an extension for connect-ion with accelerator pump. (6) Throttle spindle bushes to be ground out flush with the bore in order to minimise leaks past the throttles. (7) Throttles to V.1019 and made a very good fit in carburetter bore. (8) Control arrangement having connection between throttle and accelerator pump to V.1031. (9) Modification to accelerating pump control pedestal to V.1061. (10) Needle valve seatings to (V.1004) increased diameter of bore from .125 to .138. (11) Modification of petrol passages from floatchamber to Variable Valve to V.1005. (12) Modification of passage from floatchamber to accelerating pump to V.1055. (13) Atmospheric holes from accelerating pump to floatchambers V.1055. (14) Blanking up of original atmospheric holes on E.81436 and recesses for the same purpose on E.81437. (15) Slow running sleeve to V.1056 increase in bore from .125 - to .1719 dia. | ||