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).
Test report comparing the mileage and durability of various engine configurations and components.
| Identifier | ExFiles\Box 10\3\ 03-page185 | |
| Date | 1st October 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}6/R.1.10.38. (1) 27.G.VI. 1,500 miles. (2) 26.G.VI. 150 " (3) 25.G.VI. 283 " (4) S.E.V. Approx. 1,000 miles and 10 hours on test bed. Test Bed (Present standard small valves.) (1) Nos. 3, 4 and 5 exhaust seats cracked after 50 cycles of starts from cold. A 25/30 engine running under above conditions has not cracked. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||