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).
Investigation into the cause of a whistling noise from a G.U. carburettor.
| Identifier | ExFiles\Box 5\4\ 04-page093 | |
| Date | 5th February 1923 guessed | |
| 2 throttle and a Claudel barrel throttle; there is nothing to choose between the butterfly and piston type throttle, but Claudel throttle appears slightly quieter than the other. It was then noticed that the same G.U. carburettor when placed on different engines whistled more, or less, respectively. It was then found that the cause of whistling was the annulus in the cylinder block, made between the end of the spigot on the throttle body and the recess in the cylinder block. When this space is filled in, leaving a smooth unbroken passage, whistling ceases. CYLINDER BLOCK [Diagram with labels:] This face must be filled up to prevent whistling. CARB The low speed whistle was then investigated and found to be proceeding from the low speed jet venturi. This whistle can be | ||