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).
Car fitted with experimental features, detailing modifications to the engine, gearbox, and exhaust system.
| Identifier | ExFiles\Box 55\1\ Scan157 | |
| Date | 19th May 1932 | |
| Y5992 To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/KT.19.5.32. 16.G.IV. fitted - This car has a number of experimental features ENGINE. (a) Crankshaft. This has larger journals (2.250 dia) which enable the engine to be run up to 88 m.p.h. with standard balance weights (Chrysler Scheme Journal & 1/3 the big end) without the critical speed being felt. (b) Cylinder Head. This is a J.l. head slightly modified to fit on a standard China cylinder block. It has a 6.2/1 c/r, and 14 m.m. sparking plugs. This size of plug is fitted to enable us to get some indication of the performance of the small plug under high duty conditions. Both Lodge and K.L.G. are making such plugs and they appear promising. (c) Carbs to LeC.2924. We have fitted these with .900" dia. chokes to get good snap opening up. We are also doing work on the accelerator pump and diffusers with the object of getting the carburetters to function satisfactorily with larger chokes. We think that it may be possible to use larger chokes ultimately. We will report fully on these carburetters when we are satisfied and we know more about them. The consumption is about 15 m.p.g. at present. (d) Air Silencer. We have tried a resonance type intake silencer with some success. We are, however, sending it with the original silencer which drops about 4 B.H.P., as will be seen from the curve Rm.{William Robotham - Chief Engineer}65. (e) Petrol Feed. S.U. petrol lift fitted as we have no petrol pump design for J.l. This instrument is noisy when pumping, particularly dry, but this defect has been reduced by the manufacturers. Its operation produces flickering of the ammeter needle. GEARBOX. This is the latest production synchro-mesh box. EXHAUST SYSTEM. This is the existing standard 25 HP. exhaust | ||