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 test results of engine RPMs with varying H.T. cable lengths.
| Identifier | ExFiles\Box 4\5\ 05-page224 | |
| Date | 3rd November 1921 | |
| R.R. 299 (500 Bks.) (SP{Mr Spinney} 132, 6-51-18.) PSP 18288 ROLLS-ROYCE LIMITED. INSTRUCTIONS. To E.F.C. Order No P.B. 27. Customer's No. X 430 | Length of H.T. Cable Inches | Insulated Side negative | Uninsulated Side negative | |---|---|---| | | Advance R.P.M | Retard R.P.M | Advance R.P.M | Retard R.P.M | | 6 | 130 | 267 | 130 | 298 | | 12 | 130 | 340 | 125 | 272 | | 18 | 150 | 340 | 118 | 283 | | 24 | 140 | 338 | 118 | 288 | | 30 | 130 | 300 | 115 | 290 | | 36 | 140 | 290 | 120 | 290 | | 42 | 136 | 284 | 128 | 302 | | 48 | 132 | 280 | 120 | 300 | It will be seen that virtually, there is no variation in the spark with increase of cable length but that there is a difference in sparks from opposite sides. Signed C.G.P. This Sheet must be filed on completion of the work. | ||