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).
Results of detonation tests performed on vehicle 21-G-IV.
| Identifier | ExFiles\Box 101\3\ scan0014 | |
| Date | 9th June 1936 | |
| -3- Ha/Wym.{G. Harold Whyman - Experimental Manager}23/EW.9.6.36. Detonation Tests on 21-G-IV. Turbulent head. R.R. ignition governor. Sparking plugs KLG.831.LR.{Mr Ellor} (1) It was found necessary to retard ignition to a point 8 1/2° BTDC to rid engine of detonations at 8 - 10 m.p.h. (2) There was no appreciable gain by strengthening the mixture. (3) Spring in thermostat, increasing water temperature 8°C., brought the detonating point to 6.75° BTDC. at 8 - 10 MPH. (4) Cold air to intake gave no improvement. (5) A R.R. governor supplied by Ha/Swdl.{Len H. Swindell} showed marked improvement in detonations; i.e., very slight at 8 - 10 MPH. whilst maintaining performance 10 - 60 M.P.H. (turbulent head 10° BTDC). A comparison with non-turbulent head is shown on curve. Ha/G.B.Whyman. | ||