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).
Summary of the advantages gained by placing the engine behind the back axle.
| Identifier | ExFiles\Box 24\1\ Scan047 | |
| Date | 12th December 1931 guessed | |
| 13. At the commencement of my address I stated that there were two distinct problems, the first of which was a drastic reduction of air resistance and the second a revolutionary re-design of chassis to obtain greater comfort and controllability at high speed. It is now clear that not only are these two problems interdependent but that the key to the solution of both problems lies in the engine position. Both problems are solved by placing the engine behind the back axle. Summing up, therefor, the results obtained by placing the engine behind the back axle and the gearbox in front, in their order of importance, are as follows:- 1. The longitudinal moment of inertia of the car is increased to the maximum degree possible, but without causing tail swing, thereby increasing comfort by reducing pitching in accelerating and braking. 2. The overall weight distribution approaches the ideal for maximum braking efficiency. 3. The overall weight distribution will increase road stiction of the driving wheels when accelerating thus minimising skidding. 4. The centre of gravity of the car as a whole is as low as possible owing to the elimination of the propeller shaft. 5. The engine is 100% accessible. 6. If independent wheel springing is embodied the half axles are as long as possible thus reducing the angle on the universal joint. 7. An enclosed luggage compartment can be installed between the passengers and the engine, and can be kept cool as it is not vertically over the engine. 8. The noise, heat and smell of the engine is removed as far as possible from the passengers. 9. The controls to the gearbox do not have to pass across the back axle. | ||