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).
Efforts to reduce the weight of the Spectre engine compared to the Phantom II.
| Identifier | ExFiles\Box 96\4\ scan0003 | |
| Date | 4th July 1934 | |
| X 358 GRY{Shadwell Grylls} To Sg.{Arthur F. Sidgreaves - MD} and Wor.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} RMC. Ds. re SpectreCodename for Phantom III. Further to memo E.2/HP.4.7.34, we now know that the SpectreCodename for Phantom III engine unit is 64 lbs. lighter than the Phantom II weighed in the same condition, namely, with clutch and flywheel, clutch case and operating mechanism in position. We are disappointed with this figure as we fully expected to save 100 lbs. It is true there are one or two extras which add to the weight, such as the hydraulic adjustment of tappets, oil temperature regulator, and water temperature regulators, which would account for roughly 20 lbs, but the weight is of such vital importance that we must make every effort to obtain the desired reduction. In addition, therefore, to the items already mentioned, we are instructing a lighter fan having an aluminium hub, and light steel pulley, connecting rods of the strapped type which we expect will be lighter, and we are also looking into the question of lightening the flywheel, crankshaft, cam wheel, spring drive and oil gallery pipe and leads, also the crankcase and cylinder block casting. If the Halford type of tappet can be brought up to the required standard of performance substitution of this for the G.M. scheme would save quite an appreciable amount of weight. We shall incorporate as many of the proposals as possible in the second engine. E.{Mr Elliott - Chief Engineer} | ||