Test report discussing car performance including steering, cooling, suspension, and potential modifications.
| Identifier | ExFiles\Box 11\2\ 02-page275 | |
| Date | 14th July 1929 guessed | |
| -2- Judging from the steering as we have tried it, this has given quite good results, but we shall take the opportunity of ascertaining if it is the best compromise. It was very hot on the run down here, the atmospheric temperature rising to 28/30°C., but the running temperature of the car did not get over 90°C., with the rear bonnet shutters open. It was noticeable however that on pulling up for level crossing, the car would reach boiling point and it would then be necessary to run a long way before the temperature again became normal. This confirms our experiments that the pump ceases to circulate if the bottom water temperature gets over 90°C. In spite of the somewhat flexible lubricated road springs the car held the road very well indeed, and could be comfortably driven with one hand at 80 M.P.H. The car shows a tendency to roll when cornering fast, but as it is sprung for town work, it is a reasonable compromise. The back seats are not as comfortable as they might be, but we should recommend the 100/100 setting if a customer was going to drive as we do. As far as we have gone, we think that 21-EX has shown up so well with its own axle with the cross and side steering tube modifications which have been made by G.W.H. that we can without danger go to the .250 thick strip of rubber in the engine feet, or even more. This will reduce engine roughness. We do not think it will affect the engine roar. [Handwritten: type] While we certainly get a better steering with the standard Phantom axle, there does not seem to be any reason to rush for a change over if we can make all our cars as good as 21-EX. Knowing the differences which can exist between cars, it would perhaps be advisable to go for the ~~old 10/100~~ [Handwritten: 12.E.X] axle when we can do so without disorganizing production or involving scrap. [Handwritten: byjur pump] The modifications which G.W.H. has made to the flywheel appear to be completely successful, and we recommend that they should be immediately incorporated on production. If it were not for the engine roar, 21-EX car would be very satisfactory to put into production. For roaring I think it is worse than the other cars we have. It gives one the impression that in this particular case the exhaust may be playing a more prominent part than usual. [Handwritten: fewer] With regard to the low inertia slipper wheel which it is proposed to try, G.W.H. is insistent that to get the best result the maximum peripheral weight must be incorporated in the slipper wheels, the friction loading should not be greater than 14 lbs., and that this load should be obtained by using all the springs of a low rating, rather than stronger springs. I have asked him to give you a full [Handwritten, top right]: 32 | ||
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).