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).
15,000-mile test in France, comparing the Wraith and Bentley models, with a focus on the Wraith's performance.
| Identifier | ExFiles\Box 108\1\ scan0365 | |
| Date | 18th February 1938 | |
| 600a also 200a Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} HS.{Lord Ernest Hives - Chair} c. EV.{Ivan Evernden - coachwork} c. RHC.{R. H. Coverley - Production Engineer} c. Da.{Bernard Day - Chassis Design} c. Mx.{John H Maddocks - Chief Proving Officer} c. Ev.{Ivan Evernden - coachwork} c. Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} Hml/R.18.2.38. 15,000 Miles Test In France. Wraith & Bentley. We were able to try both these cars under widely varying conditions. We climbed up 5,000 ft. with the Wraith. A brief summary of our impressions are as follows:- WRAITH. This car is so controllable in comparison with the 25/30 that it is automatically driven at higher average speeds. Owing to the alteration in tyres the overall top gear ratio is actually lower than that of the 25/30. Unless Sales consider that a higher axle ratio will spoil English sales, we recommend that we should use the F.111 axle gears, which will give us a 3% higher overall ratio than the present standard 25/30. Tests indicate that this axle ratio will bring the petrol consumption back to that of the 25/30 when driven in the same way. The distributor failure is the only one in the 6,000 miles so far run. We believe this is entirely due to engine torsional vibrations caused by the continuous high engine revs. which are maintained due to the low axle ratio. We recommend that whether a Rolls-Royce or a Delco distributor is used, a flexible drive should be incorporated at this point. This is standard on all American cars, and has already been provided for in our new engine designs. The oil consumption of this car, which concerned us at first, has now settled down to something like 1200 m.p.g., and there is now no oil leak from the main bearing so we are no longer worried in this direction. The engine mounting requires one or two small modifications which are being dealt with, and the one or two engine vibration periods noticed by Sales when they | ||