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).
Design and performance of the Peregrine carburetter and induction pipe, including throttle valve size and spatial constraints.
| Identifier | ExFiles\Box 1\10\ B001_X106 TO X 110-page070 | |
| Date | 23th August 1932 | |
| X108. To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} E.9/HP.23.8.32. c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} Peregrine Carburetter and Induction pipe. --------------------------------------- Please find herewith blueprints of LeC.3157 and LeC.3169 showing proposed designs for the above. Originally we decided that the throttle valve for this carburetter would be big enough 1-1/2" in diameter, which is .125" bigger than we were using on the 20/25 chassis. In comparing our design finally with what was being used on the car we came to the conclusion that the 1-1/2" throttle valve represented a restriction which would definitely reduce our maximum power, and we, therefore, increased the diameter to 1.625". We see no reason now why this carburetter should not give the same maximum performance that is being obtained with the 1.625" S.U. on the Peregrine, and we think it should be intermediate in performance between the single and double S.U. induction systems. The somewhat forward position of the steering box on this chassis has restricted the room available for the carburetter, but we found we could not move the steering box back without causing the column to cut into the floorboards on the lower rakes of steering, and the side steering link to foul the external stiffener on the frame connected to the dashboard. We think, however, the carburetter has gone in very well in the space available, and we believe the length of uptake to the induction pipe may be found satisfactory. This uptake could be longer but for the steering box. The hot spot jacket on the induction pipe has had to be definitely restricted to the tee joint of the induction pipe, and does not circulate round the immediate piece of uptake above the throttle. This condition has had to be accepted owing to the near presence of the sparking plugs of Nos.3 and 4 cylinders on either side of the uptake, and the necessity for providing a safe sparking gap around the live portions of the plugs. We think, however, the provision for heating will | ||