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).
21,000 miles of road testing, including details on engine unit performance and modifications.
| Identifier | ExFiles\Box 108\3\ scan0194 | |
| Date | 9th May 1938 | |
| To:-sg.{Arthur F. Sidgreaves - MD} From Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} C. Hs.{Lord Ernest Hives - Chair} C. By.{R.W. Bailey - Chief Engineer} C. Mc. C. Sa. C. Rm.{William Robotham - Chief Engineer} C. Ld. C. Wh. C. Gr.{George Ratcliffe} C. Mn. 8 600a RM{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux}3/WH.9.5.38. TESTS IN FRANCE. 20.C.VI. - 25/30. Report on 21,000 miles running including 15,280 miles run from Chateauroux, 2117 miles by Mx.{John H Maddocks - Chief Proving Officer} as reported in Mx.{John H Maddocks - Chief Proving Officer}1/W.4.4.38, and the remainder in England. Specifications HRS/WHB/31.1.38. Modifications during mileage Rm{William Robotham - Chief Engineer}/Imw.{Ivan M. Waller - Head of Chateauroux}8/WH.6.4.38. ENGINE UNIT W.III NO.7. Subject to the modifications referred to, the engine appears suitable for production. It was smooth and silent up to 3600 r.p.m; vibration was noticeable at this speed and above. With the axle ratio that it is proposed to standardise, this is equivalent to 74 m.p.h. in top gear. High engine speeds in top gear were more easily obtained and held than with the present standard 25/30. Larger rear tyres were therefore fitted for part of the mileage to represent the higher axle ratio which has been instructed for production. On top gear 4000 r.p.m. could still be maintained and 4450 r.p.m. reached under favourable conditions. The standard of smoothness throughout the range deteriorated slightly towards the end of the mileage and a rumble was audible when idling which could be eliminated by | ||