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).
Comparing the performance of an 8-litre engine against a 7.6-litre unit.
| Identifier | ExFiles\Box 123\3\ scan0074 | |
| Date | 13th December 1933 | |
| X4750 To Sg.{Arthur F. Sidgreaves - MD} from Ha/Rm.{William Robotham - Chief Engineer} Cc. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} Cc. Ry. Rm.{William Robotham - Chief Engineer} Cc. Hvs. Ha/Rm.{William Robotham - Chief Engineer}9/KT.13.12.33. <7111> 8 LITRE ENGINE. Referring to Sg{Arthur F. Sidgreaves - MD}7/E12.12.33. The 165 B.H.P. in our memo referred to the 7.6 litre unit. We attach a curve showing a direct comparison between the power unit we are putting in the Vulture and the units fitted in M.Y. chassis. Since we have the same valves in the 8 litre engine as in the 7.6 litre we get very little more top power under similar conditions, the gain shown on the attached curve being largely due to the bigger carburetter and high compression ratio, i.e. fit these to the M.Y. engine and we should get at least 165 B.H.P. Where the 8 litre engine will always score over the 7.6 litre is in improving the cars acceleration at intermediate speeds by about 5% for the same degree of roughness. Ha/Rm.{William Robotham - Chief Engineer} | ||