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).
Test results and specifications for carburettor acceleration and metering.
| Identifier | ExFiles\Box 13\3\ 03-page432 | |
| Date | 20th June 1932 | |
| -3- Bs{A J. Barnes - Assistant Manager}/Swdl.{Len H. Swindell}2/MA.20.6.32.Contd. Now that the slow running feed is taken from the diffuser, the filter could be moved to a more useful position, somewhere before the petrol enters the mechanism. ACCELERATIONS. Acceleration tests have been carried out on the test bed unit in the following way:- (a) Time taken to open up from (500 RPM throttled back) to developing 56 BHP, the brake being set full throttle at 1000 RPM. (Expanding carburetter 3 secs), (2-1/2 S.U. carburetters 2-1/2 secs). (b) Time to open up from (250 RPM throttled back) to develop 30BHP, the brake being set at full throttle 550 RPM. (Expanding carburetter 2 secs) (2-1/2 S.U. carburetter 2-1/2sec). It is the size and position of the bleed holes which are of the most importance to good acceleration and should be in the same position as shewn on (E.83066). The top row of holes should consist of 4, .039 dia and the bottom row 4, .055 dia holes. METERING. Good metering can be obtained by using the following. Taper needle to V.1373, being straight sided taper .145 dia at the large end and .083 dia at the small end, the taper length being 1.075. (b) Main jet to V.1336 having an orifice .130 dia. | ||