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 of distributor dimensions listing relative and absolute values in inches.
| Identifier | ExFiles\Box 65\3\ scan0077 | |
| Date | 3rd September 1927 guessed | |
| -3- Distributor dimensions. Relative. | Absolute(inches) Pitch (P) = | 1.000 | 1.26 Make ratio (M) = | .556 | .700 Range (R) = | .336 | .423 Forward overlap at full advance (Fa) = | .060 | .075 Forward overlap at full retard (Fr) = | .396 | .498 Backward overlap at full advance (Ba) = | .242 | .305 Backward overlap at full retard (Br) = | -.095 | -.118 Width of brush (B) = | .151 | .190 Length of segment (S) = | .595 | .750 Distributor dia. (D)= | 1.905 | 2.400 Contd. | ||