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).
Comparison table of relative distributor dimensions for Watford and Lucas models, with suggested new dimensions.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 171 | |
| Date | 13th June 1927 guessed | |
| -4- Contd. Relative distributor dimensions. Watford. Lucas (Jump spark) Lucas (Wipe contact) Suggested relative dimensions. Pitch (P) 1.000 1.000 1.000 1.000 Make ratio (M) .690 .575 .575 .56 Range (R) .280 .333 .33 .34 Forward overlap at a full advance (Fa) .126 .004 .165 .10 Forward overlap at a full retard (Fr) .406 .337 .495 .44 Backward overlap at full advance (Ba). .286 .182 .19 .20 Ditto at full a retard (Br) .006 -.151 -.14 -.14 Width of brushes (B) .143 .427 Length of segment (S) .580 .183 Brush + segment. .72 .61 .78 .74 B + S + M.{Mr Moon / Mr Moore} 1.41 1.185 1.355 1.30 Insulation distance (I) .404 .393 .385 .36 Distributor dia. (D) 1.910 1.910 1.910 1.910 Contd. | ||