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 different ignition systems.
| Identifier | ExFiles\Box 40\2\ Scan205 | |
| Date | 13th June 1927 guessed | |
| -4- Contd. Relative distributor dimensions. Watford. Lucas Lucas Suggested (Jump spark) (Wipe relative contact). dimensions. Pitch. (P) = 1.000 1.000 1.000 1.00 Make ratio (M) .690 .575 .575 .56 Range (R) .280 .333 .33 .34 Forward overlap at full advance (Fₐ) .126 .004 .165 .10 Ditto at full retard (Fᵣ). .406 .537 .495 .44 Backward overlap at full advance (Bₐ) .286 .182 .19 .20 Ditto at full retard (Bᵣ) .006 -.151 -.14 -.14 Width of brush (B) .143 .427 .176 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. | ||