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).
Table detailing distributor dimensions in both relative and absolute (inches) values.
| Identifier | ExFiles\Box 65\3\ scan0063 | |
| Date | 23th August 1927 guessed | |
| -3- Distributor dimensions. Relative. | Absolute(inches) Pitch (P) = 1.000 | 1.26 Make ratio (M) = .558 | .705 Range (R) = .328 | .413 Forward overlap at full advance (Fa) = .050 | .060 Forward overlap at full retard (Fr) = .376 | .473 Backward overlap at full advance (Ba) = .258 | .325 Backward overlap at full retard (Br) = -.070 | -.088 Width of brush (B) = .151 | .190 Length of segment (S) = .595 | .750 Distributor dia. (D)= 1.905 | 2.400 Contd. | ||