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).
Lap speed tests conducted with new Avon and India tyres to ascertain power loss.
| Identifier | ExFiles\Box 97\5\ scan0345 | |
| Date | 4th May 1939 | |
| -2- Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden}4/JH.4.5.39. The Avon and India tyres were fitted new and run straight off at maximum speed in order to ascertain whether the very high loss obtained on the dyno. rig with new tyres on their first run had any marked effect. The speeds for the starting laps on these tyres were as follows - m.p.h. Lap No. India. Avon. 1 85.15 85.28 2 85.87 86.7 3 86.25 87.45. 4 86.7 88.38. 5 86.6 88.38. Attached is a power curve obtained on 7.B.V. on the day following the Brooklands tests, showing that the horse power available at the hubs only varies by about 1 H.P. over the range of lap speed covered. Rm{William Robotham - Chief Engineer}/T.A.Swinden. | ||