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 of secondary ignition voltage curves for the Wraith model, using both Rolls Royce and Delco-Remy distributors.
| Identifier | ExFiles\Box 168\3\ img154 | |
| Date | 5th April 1939 | |
| WRAITH IGNITION SECONDARY VOLTAGE CURVES ROLLS ROYCE DISTRIBUTOR 2250 R.P.M VOLTS 4000 2000 0 PLUG SPARKING PLUG NOT SPARKING VCH 7 Delco - Remy DISTRIBUTOR 2250 R.P.M PLUG SPARKING PLUG NOT SPARKING S.G.L. 5.4.39 | ||