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 tests between a standard and a special ignition coil.
| Identifier | ExFiles\Box 164\5\ img402 | |
| Date | 4th February 1939 | |
| 6119. EXPERIMENTAL DEPARTMENT. Rm{William Robotham - Chief Engineer}/RC.{R. Childs}3/JH. 4th. February, 1939. Messrs. Delco-Remy & Hyatt Ltd., 111, Grosvenor Road, LONDON. S.W.1. For the attention of Mr. B. Rushton. Dear Sirs, We have now completed comparison tests between your standard coil, and a special coil which you have designed to decrease the running temperature of windings. The following results were obtained :- Test. Standard Coil. Special Coil. Primary Resistance 2.91 ohms. 3.875 ohms. Primary Impedance 3.71 ohms. 5.1 ohms. Primary Inductance .00732 Henries. .0106 Henries. Maximum Temperature 178°C. 126°C. (attained on car). Output cold. 10.0 K.V. 9.3 K.V. Output Hot. 6.9 K.V. 7.1 K.V. 'Pick-up' Performance Misfires on engine. when hot. Good. 'Loading up' performance Misfires on engine. when hot. Good. The General Running Performance of the special Coil is the better of the two, especially when hot; this is due to a lower maximum temperature. On the cold starting tests carried out in a temperature of 6° Fah., the standard coil made a good start in 6 seconds, the special coil was not so good taking 13 seconds. Attached are curves showing Input and Output characteristics. In this case the hot condition is obtained by testing the coil, in conjunction with a Delco-Remy distributor running at a speed of 800 r.p.m. for 1 1/2 hours, during which Cont'd.{John DeLooze - Company Secretary} | ||