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).
Graph comparing the performance of different chassis ignition coils.
| Identifier | ExFiles\Box 164\5\ img325 | |
| Date | 24th May 1937 | |
| COMPARISON OF CHASSIS IGNITION COILS A = LUCAS COIL IN R.R. TYPE CASE B = LATE TYPE LUCAS COIL IN METAL CASE N1 = R.R. COIL TO D.T.S. 573. UNFILLED N2 = SAME AS N1, BUT IMPREGNATED & FILLED WITH BITUMEN COMPOUND N3 = SAME AS N1, BUT IMPREGNATED & FILLED WITH BITUMEN COMPOUND FAULTY COIL. FAILURE DUE TO FRICTION BETWEEN PRIMARY & SECy. CONNECTION & INSULATING TUBE, CAUSING SECy. WIRE TO FRACTURE. X-AXIS: SECONDARY KILO VOLTS Y-AXIS: SPARKS / SEC. | ||