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).
Weight comparison table of components between the E.A.C. Engine and the 40/50 Engine.
| Identifier | ExFiles\Box 3\2\ 02-page103 | |
| Date | 1st February 1924 guessed | |
| (2) E.A.C. ENGINE SECTION | L.O.P. | LBS. WEIGHT | % OF TOTAL WEIGHT Dist: Drive. | | 4.0 | .42 Water pump drive. | E.{Mr Elliott - Chief Engineer} 71152 | 4.75 | .5 Water pump. | E.{Mr Elliott - Chief Engineer} 70527 | 6.44 | .69 Oil pump and Filter. | | 5.6 | .6 Wheelcase and Fitts: | E.{Mr Elliott - Chief Engineer} 70932 | 8.75 | .92 Carburetter. | | 10.25 | 1.09 Mag. & Drive. | | 15.37 | 1.63 Piston. | E.{Mr Elliott - Chief Engineer} 70511 | 15.62 | 1.72 Camshaft Brgs. Wheel comp: | | 17.12. | 1.82 Connecting rods. | E.{Mr Elliott - Chief Engineer} 70447 | 17.16 | 1.83 Tappets and Guides, push rods, rockers shafts & | | 25.62 | 2.72 Dynamo. | | 31 | 3.3 40/50 ENGINE SECTION | L.O.P. | LBS WT. | % OF TOTAL ENG:WT. | INCREASE OR SAVING OF WT. ON E.A.C. LBS. Water pump. | | 8.5 | 1.03 | Saved 2.16 Wheelcase and Fitts. | | 8.56 | 1.04 | Increase .2 Carburetter. | | 19.75 | 2.42 | Increase 9.5 Wtr. Conn: to thermostat)less wtr. pipe to rad: | E.{Mr Elliott - Chief Engineer} 22118 | 13.75 | 1.7 | Mag.& Drive | E.19475 | 18.5 | 2.27 | Saving 3.13 Piston. | E.{Mr Elliott - Chief Engineer} 20562 | 16.51 | 2.02 | Saving .98 Camshaft. | E.{Mr Elliott - Chief Engineer} 17153 | 16.62 | 2.03 | Increase .5 Conn: Rods. | E.{Mr Elliott - Chief Engineer} 17160 | 20.06 | 2.5 | Saving 2.9 Tappets etc. | E.{Mr Elliott - Chief Engineer} 22771 | 15.0 | 1.84 | Increase 5.62 Dynamo. | | 27.5 | 3.4 | Increase 3.5 | ||