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).
Body design, weight, and aerodynamics of the 10-EX model, comparing it to competitors and suggesting improvements.
| Identifier | WestWitteringFiles\Q\July1927-September1927\ Scan124 | |
| Date | 13th September 1927 | |
| [Crossed out: BJ.] FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} C. to HS.{Lord Ernest Hives - Chair} re. 10-EX. Handwritten: X8774 [Crossed out: 48840] 48600 With reference to BJ17/E12927., we note that the Sales officials have little doubt that a sports body weighing 7 cwt. can be designed and made. We have always appreciated this, and have existing bodies on rival chassis as proof, but we do doubt whether our leading coachbuilders are able to achieve this. To do so would mean that they are now able to save 40% on the weight of their construction of three years ago. Weymann with his radically lightened methods of design and construction is only able to claim a 30% saving, and our leading coachbuilders have not made any startling departures from their old and orthodox methods. We do not agree that 10-EX. is a mongrel or crossbreed in appearance, and take the remark to apply to the construction. We have the weights of the car before and after the tail was added. The addition of weight cannot be measured, as the removal of the old coachwork and wheel carrier compensated for it. A tail producing a clean exterior with wings and screen of minimum head resistance are essentials of a really fast car. A wheel at the rear which is exposed acts as an air churn. It is much easier to gain by considering the outward configuration of the car than by getting more out of the engine. The design of body on 10-EX. is the best we know of at present from the standpoint of minimum tractive resistance with maximum comfort and effectiveness of its units, screen, wings, etc. There are however two improvements which we would wish to include in a new body, a concealed hood, and a metal tonneau cover for the rear seats which would form part of the seat when opened. DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} [Circular Stamp: RECEIVED] | ||