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).
Responding to component performance remarks following a 15,000-mile test of the 18-G4 model in France.
| Identifier | ExFiles\Box 5\1\ 01-page168 | |
| Date | 5th July 1933 | |
| To Sg.{Arthur F. Sidgreaves - MD} From Hs.{Lord Ernest Hives - Chair} c WOR.{Arthur Wormald - General Works Manager} E c DA{Bernard Day - Chassis Design} c EV.{Ivan Evernden - coachwork} c PH. 18-G4 15,000 MILES TEST IN FRANCE. Replying to Sg.{Arthur F. Sidgreaves - MD}1/WT.4.7.33. We do not understand the remarks about the S.U. design of air valve. The carburetter fitted to 18-G4. is the standard design of S.A. carburetter except that there is a single air inlet which enables a silencer to be fitted. There never has been any suggestion of fitting a semi-expanding carburetter similar to the 40/50 on the 25 HP. The sticking of the air valve on the standard carburetter we know is one of its inherent faults. Radiator & Fittings. The test has confirmed that the Marston matrix is more efficient than the honeycomb type. We are proposing to standardise this type of matrix on all 25 HP. cars. As regards the Fan, this is not being modified; we shall use the standard 25 HP. fan. We are not surprised that the fan does not make much difference at high speeds. The main purpose of the fan is for low speed and town work. The radiator conditions will therefore be the same as the 25 HP. except that we shall have the advantage of the improved efficiency of the matrix. We do not understand the remarks that it is proposed to employ a thermostat without radiator shutters. There has never been any suggestion of altering the 25 HP. This car was tried in London before it went to France. Fan. We are not proposing to alter the Fan. The small fan was purely an experimental test. Low Inertia Damper. We stated in our report that the Ferodo discs were being tried out as an alternative to the present cotton discs. This was purely an experiment and we are not proposing to alter the material; cotton discs will still be used. Gearbox. The oil leak from the foot brake shaft is the same as on all 25 HP. synchro mesh gearboxes. Although we have delivered several hundred of these cars we have not yet had a complaint. We shall endeavour to improve this point but it is not a serious matter. Rear Axle. This is the standard 25 HP. and we do not propose to make any alteration. | ||