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).
Page 2 of a letter from Zenith Carburetter Co. regarding needle seating dimensions.
| Identifier | ExFiles\Box 122\3\ scan0145 | |
| Date | 21th July 1939 | |
| THE ZENITH CARBURETTER CO. Limited. Sheet No. 2 Messrs. Rolls-Royce Ltd, Derby, 21.7.39. ..endeavour to keep the dimensions of needle seatings as small as possible. With large needle seatings there is a long line of contact involved and since the needle is always operating in an unstable condition we have found it advisable to keep the extent of the line of contact as short as possible. We ourselves have made a .140" needle and seating which is tight, but we are afraid that in production we might be unfortunate to run up against a great deal of trouble, which might unwittingly be experienced by your goodselves. We think we are just in the right line of approach by recommending a small needle seating, and trust you will be able to have the pump pressure modified accordingly. Yours faithfully, THE ZENITH CARBURETTER CO.LTD. A L Palmer AEP/GD. | ||