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).
Performance comparison report on 25 HP and 20 HP models, including maximum speed test data.
| Identifier | ExFiles\Box 24\5\ Scan312 | |
| Date | 25th August 1930 | |
| -3- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/MJ.25.8.30.Contd. reached on this gear in comfort. We think that the Graham Paige have cleverly exploited the obsolete R.A.C. rating formula and will get a good reputation when compared with the average 30 H.P. car. On the other hand the 25 HP. R.R. must XX similarly suffer due to its short stroke. We have nothing at all to spare on the 25 HP. when competing with these cheap American cars for performance. On the acceleration curves we give, that of the 40/50 was taken in France on the poorest fuel obtainable, before the heat to the hot spot was increased - hence it is not up to standard at low speeds. SPEEDOMETERS. The calibration curves given indicate what we already know. DATA. The car weights, tyre dia., direct drive ratio, were all accurately measured on the track. 20 HP. MAXIMUM SPEEDS. We took the opportunity of getting some 20 HP. maximum speeds while on the track. The results obtained were as follows :- Mile. Lap Speed. GLN-68 Saloon o Fitted with 112° Camshaft & 5.75 C.R. 69.77 68.03. (Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/MJ.26.4.30). GXO-15 Open Touring. 66.18 64.26. 14-G4 Cabriolet (10,000 Miles car) 64.29 62.64. Production Chassis. 62.5 61.48. These results are interesting in that they shew the futility of comparing chassis with bodied cars for speed owing to the difference in windage. Also the appreciable | ||