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 for the E.A.C. engine versus the 40/50 engine.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan99 | |
| Date | 12th July 1923 guessed | |
| (1) E.A.C. ENGINE. SECTION. | L.O.P. | LBS. WEIGHT | % OF TOTAL ENG. WT. Oil Filler | | .56 | .059 Starting carb. | | .75 | .08 Oil relief Valve. | | 1.25 | .13 Dynamo suspension. | D.70248 | 1.25 | .13 Controls. | | 1.75 | .19 Oil pump drive. | | 1.75 | .19 Bottom water pipe. Pump to cylinder. | | 1.875 | .2 Wiring. | | 3.0 | .32 Sparking Plugs (12) | | 3.5 | .373 Dist: and Governor. | E.71146 | 3.56 | .32 Idler gear. | E.71158 | 3.8 | .40 40/50 ENGINE. SECTION. | L.O.P. | LBS. WT. | % OF TOTAL ENG:WT. | INCREASE OR SAVING OF WT: ON EAC. ENG: LBS. Oil cock Actuation. | | .75 | .092 | Extra cyl: lubrication. | E.22199 | 1.375 | .16 | Controls. | E.23168 | 3.0 | .367 | Saved 1.25 Oil Fitts: | | 3.0 | .367 | Governor Drive. | E.22200 | 3.25 | .400 | Sparking plugs. | | 3.5 | .430 | Dist: and Gov: Oil Pump and Air pump. | | 17.25 | 2.12 | Idler gear. | E.17170 | 3.5 | .43 | Increase .34 | ||