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).
Vehicle ride characteristics, performance, and body design considerations.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan049 | |
| Date | 30th October 1930 guessed | |
| (2) ORIGINAL For heaven's sake do not increase the height of the roof, or seats, because it makes springing more difficult, if not impossible, for low speed comfort and high speed stability. We have arranged that the pots in the floor must be avoided and this is demanding the hypoid axle and some alterations to the cross members which we have arranged for. The propeller shaft has been increased from 2.25 to 2.5 dia. to prevent whirling at the increased length and engine revs., and the flywheel is also to be modified to reduce a similar vibration at very high speeds. With this engine mounting the 5.25 compression ratio seems as smooth as any I have experienced, and detonations were quite absent. The car was not capable of very high speeds, but at about 55/60 it was very much inclined to roll and wander with 6 full weight people, and it was agreed that the springs, especially the rear, were too flexible for this large, fairly heavy body and full load. I believe that for town carriage work with one passenger and driver it might be found very comfortable at low speeds - i.e. 40 MPH. and under, and would suit some people if they were content to go slowly with full load. It must be realised that this is the type of springing that USA. people like. The P. 1. car that Olley brought over had exactly the same characteristics. It was also a short body with good position of rear seats, a canvas top, and all to shew little ill of the very flexible springs - an original RR. feature but not so suitable for the high speeds of today. Before ordering a stock of bodies it is absolutely necessary to have a good, approved, and well tested sample one that can have a 10,000 miles test, and be approved by the technical staff. 18-G-4. is a wonderful body for room (but is really too big for our 25HP. chassis) - i.e. 6 facing forward with comfortable front seats - i.e. raked steering. R.{Sir Henry Royce} | ||