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).
Horsepower loss and the requirement for a Duplex Exhaust System for a 24-hour run.
| Identifier | ExFiles\Box 160\3\ scan0049 | |
| Date | 13th January 1939 | |
| 1379 Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe} Rm{William Robotham - Chief Engineer}6/R.13.1.39. Will you please let me have a note every day telling me what you are doing, even though you may not have made much progress. I attach a horse-power curve produced by Salt, from which it is apparent that when we go for the 24 hour run we shall have to fit a Duplex Exhaust System, because at the present moment we lose 12 horse-power between the cut-out and open exhaust. It does not look for a moment as if it would be worth running the large carburetters, anyhow for road work. Rm.{William Robotham - Chief Engineer} | ||