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).
Publicity, Wraith model modifications, engine vibrations, engine development, and gear ratio performance.
| Identifier | ExFiles\Box 161a\3\ scan0003 | |
| Date | 6th January 1939 | |
| -2- B.11. BY.1/G.6.1.39. PUBLICITY. The Paulin car is being prepared for Sr's run on an Autobahn. Cx.{Major Len W. Cox - Advertising Manager} is arranging for the "Autocar" to send up someone to write up the "Engineering Department". [Handwritten] SG{Arthur F. Sidgreaves - MD} TO SEE RM{William Robotham - Chief Engineer} NEXT WEEK. WRAITH. MODIFICATIONS. There are nine modifications, which either require work being done or examination to be made of certain parts. The position is fully outlined in BY.10/N.4.1.39. which has been circulated. ENGINE VIBRATIONS. The trouble which arose over this has been cleared for production by introducing a similar inertia in the camshaft wheel as that on 'R' Series of 20/30. In the meantime we have two further experiments in hand :- (a) Rubber blocks of considerably increased diameter, with the object of increasing deflection. (b) The Metalastik coupling has been designed and produced, and is being tested on 8.B.5, also the test bed unit is fitted with one of these, and they appear to be the proper solution of the difficulty, as they give very much increased elasticity which we hope will enable us to return to the light cam wheel, which in turn would avoid rattles which have been complained of by the Test Department since the inertia of the wheel was increased. [Handwritten] RM{William Robotham - Chief Engineer} SHOULD FINALISE ENGINE DEVELOPMENT. A B.60 cast iron engine is being fitted into 24-G-VI. chassis with the object of obtaining a preliminary road test demonstrating the engine characteristics in relation to a car we are well acquainted with. GEAR RATIO RELATIVE TO PERFORMANCE. (a). The overall gear ratio of Wraith as originally produced was 3.72% lower than the last series of 25/30. (b). Owing to necessities from the point of view of bearing life, it was agreed to increase the overall ratio, and this was done to the extent of making Wraith as now on production 2.7% higher than the last series of 25/30. This represented an increase over the Wraith as originally designed of 6.4%. No intermediate ratios to these are available owing to the limitations of the possibilities in the bevel gears. | ||