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).
Engine specifications and design considerations for a new car model, including supercharging and comparisons to previous models.
Identifier | ExFiles\Box 30\2\ Scan074 | |
Date | 30th August 1932 | |
-2- Hs.{Lord Ernest Hives - Chair}9/KT.30.8.32. cont'd.{John DeLooze - Company Secretary} We have assumed the same efficiency as on 19-C-IV. (The car Sg.{Arthur F. Sidgreaves - MD} had in France) which, although he admitted had plenty of power, was considered to be totally unlike an R.R. car. We are assuming this power from the 12 cyl. because by the time the car is produced we expect to have made a certain amount of progress, and also because the engine being bigger, will most of its time be run under throttle conditions. We strongly hold the view that the 3 x 4 1/4 engine is too small to meet all the requirements. We recommend 12 cyl. the present 25 HP. size which is 3 1/4 x 4 1/2. Sg.{Arthur F. Sidgreaves - MD} has suggested what we consider a very good compromise and that is, the engine shall be designed for 3 1/2 bore. We shall be prepared however to fit a 3 ins. bore if there is a demand. This means that for customers who do not wish to go fast, or those who object to the increase in tax, we can still supply a car at the same tax as at present, namely £44. We shall, however, with the larger engine be able to produce a much more satisfactory Continental type car, and it should also be a better car for export, where taxation is not on the same scale, and also where we shall have to compete with the large American cars. The alternative which may be suggested is to fit a supercharger. We consider this is far too experimental at the present time to tie up a design to be dependent upon the supercharger for extra power. When we went from P.I to P.II we had considerable difficulty in convincing customers of any increase in performance. Fortunately, however, the P.II had a greatly improved appearance. It also had a different type of springing which enabled us to sell cars to existing P.I owners. We believe we are right in saying approximately 75% of 40/50 sales are to previous owners of 40/50, so that in introducing a new car, we have got to make it attractive to the existing owners. If we get a big enough engine we can satisfy the man who wants performance. We also have a much better chance of satisfying a customer who requires silence and smoothness because we can then use more effective silencers both on the inlet and exhaust. One does not expect that the new car will score greatly over the P.II. for appearance. The bonnet will be shorter, but we cannot make the car much lower. | ||