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).
Dynamometer testing of an axle and gears for an 8-cylinder car.
| Identifier | ExFiles\Box 123\5\ scan0147 | |
| Date | 4th November 1938 | |
| Spare 1044. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}1/MH.{M. Huckerby}4.11.38. To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Da.{Bernard Day - Chassis Design} c. Hdy.{William Hardy} c. Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} AXLE FOR 8-CYLINDER CAR. We have fitted a B.II axle to the P.III dynamometer chassis with a view to determining the suitability of 8 1/2" .650 offset gears for the 8-cylinder car. Top gear full throttle on the P.III was used to simulate 3rd. for the Straight 8 and 2nd. speed on the P.III for 1st. on the "8". A pair of 10/43 gears with a previous dynamometer history of 20 hours on 2nd. on a Bentley did not show up well after 6 hours P.III top gear. A new pair was fitted and run 30 hours on top gear using Hi-Press cooled to 90°C. The surface although marked was in good condition. After 17 hours on 2nd. (1st. speed torque for the "8") the pinion teeth failed breaking at the root. These gears are not, therefore, suitable for the Wraith Replacement. Further testing will show whether they would be adequate for the 8-cylinder Bentley with a high 1st. speed ratio. A drawing of the semi-floating version of the 10" .850 offset axle is therefore required. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||