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).
Estimated weight difference comparison between the 1.85 litre and 2.84 litre rear axles.
| Identifier | ExFiles\Box 114\1\ scan0241 | |
| Date | 10th August 1939 | |
| 1015 Rm.{William Robotham - Chief Engineer} from Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}T.N. c. B.V. (text has strikethrough) c. Da.{Bernard Day - Chassis Design} (text has strikethrough) Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}8/G.10.8.39. REAR AXLE. ESTIMATED WEIGHT DIFFERENCE BETWEEN 1.85 LITRE AND 2.84 LITRE REAR AXLES. The pieces considered in this estimate are the centre casing and end covers and the parts contained within these, i.e. parts influenced principally by engine size and not by car weight. It has been assumed that the rear axle reductions will be of the order 4.56/4.1. These weights are: 35 lb. for 2.84 litres, 26 lb. for 1.85 litre size, showing a saving of 9 lbs. (The total weight of a rear axle for B.V. is quoted as 150 lb. complete with 1/2 shafts, axle tubes and wheel bearings (1.5 hypoid axle).) To achieve this weight saving the 1.85 litre axle would have a 6.3" crown wheel. If there are to be only two rear tracks for all cars, there need only be two axles, but the smaller axle must be designed for 2.8 litre torque. Da{Bernard Day - Chassis Design}/HDY.{William Hardy} | ||