Table comparing the weights of various engine units and components in pounds (lbs).
| Identifier | ExFiles\Box 18\1\ Scan082 | |
| Date | 3rd May 1936 | |
| X758 ENGINE UNIT WEIGHTS. LBS. CHINA(Experimental Engine). PEREGRINE(Experimental Bentley car never produced / Aero Engine). J.III. 40/50 Engine. 565 417 480 871 - PII Gearbox. 115 110 115 201+ TOTAL. 680 527 595 1072 * Clutch pit included 40/50 Crank 100 lbs. Spectre(Codename for Phantom III) Crank 70 lbs. PIII 3-5-36 PII PIII {1929/30 {1935 {1936 {1939 | ||
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).