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).
Modifications to the Goshawk 11 carburetter to address a noisy intake and float chamber issues.
| Identifier | ExFiles\Box 5\4\ 04-page028 | |
| Date | 17th October 1931 | |
| To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to CJ. c. to Wor.{Arthur Wormald - General Works Manager} c. to Da.{Bernard Day - Chassis Design} c. to HY.{Tom Haldenby - Plant Engineer} X4228 RB{R. Bowen}/G17.10.31. GOSHAWK 11 - CARBURETTER. X.4228. With regard to the reported noisy intake of Goshawk 11, we felt sure that this would be proved to be due to the double ports and the air blowing over the sharp edge when entering one port with the other valve closed. Though this often occurs in nearly all multiple cylinder engines, it may not be so bad as in the particular head we have designed. We have send you a drawing shewing how this can be altered, and we feel sure that this alteration should result in at least slightly reducing the noise. At the same time we have at-least-slightly completed the design of the carburetter fitted with a silencer which can be used should it be advantageous. Some improvements have been made while altering the carburetter, such as the length of the stroke of the air valve, which should give the experimenter a better chance of varying the ports to get the mixture absolutely equal at all speeds and throttle openings. Regarding your trouble with the floatchamber, we are sure this was due to the float being made of too thick material, and therefore too heavy, but at the same time we have increased the diameter of this chamber and float so as to make it easier to get right and its action more vigorous. At the side of this chamber we have arranged a small carburetter with a moving throat, similar to the starting carburetter that you suggested should be put on the 40/50 H.P. We are not proposing contd:- | ||