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).
Instruction sheet detailing ignition tests on a 20 HP chassis, comparing ballast resistances and ignition systems.
| Identifier | ExFiles\Box 54\5\ Scan314 | |
| Date | 25th March 1929 | |
| RR 238 (150 BKS.) (DB {Donald Bastow - Suspensions} 461-8-12-24) MP 306975 X5680 ROLLS-ROYCE LTD. INSTRUCTIONS. To: E7C 25 - 3 - 1929 Order No.: WD {Mr Wood / Mr Whitehead} 48 Customer's No.: Ignition tests on 20 H.P. chassis 12.G IV. Tests have been made on the above chassis in order to determine the amount of margin of satisfactory performance we have on the 20 H.P. chassis using the recently standardized 1 1/4 value ballast resistance. At the same time, the performance of the Watford ROI magneto was observed as compared with the R.R. Battery ignition system. Normal voltage was used the dynamo charge being switched off. We found that the 1 1/4 value ballast was OK when thoroughly heated up by the engine and gave no misfires on the "pick up". With a double value ballast resistance occasional misfires Signed (contd) This Sheet must be filed on completion of the work. | ||