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 conducted on a B-23-AE engine.
| Identifier | ExFiles\Box 82\4\ scan0332 | |
| Date | 9th June 1936 | |
| -2- Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}23/KW.9.6.36. Detonation Tests on B-23-AE. Cylinder head EV.{Ivan Evernden - coachwork}86, 109 c.c's, 6.8 : 1 C/R.{Sir Henry Royce} Rolls-Royce ignition governor standard condition. Ignition timing 13° BTDC fully advanced. Water temperature, as shown on thermometer, 78°C. (1) Test under standard conditions, detonations are in evidence at low speeds from fully advanced position to 10 notches retarded on ignition lever; i.e., 15° retard. (2) Cold air intake arranged by flexible pipe from carburetters through side of bonnet. Improvement of 1.5°. (3) To obtain an improvement of 1.5° by mixture strength the stand pipe has to be dropped .035", mixture far too strong. (4) Spring fitted to thermostat thus increasing the water temperature by 7°C. causes earlier detonations by 1.5°. (5) Experiments with spark plug gaps - variation of gap does not affect detonations. Plugs used, ALG-S50. Plug gap .015" to .040" .025" best position for slow running and pick up, .035" gap, slight misfires on pick up. .040" bad misfires pick up. | ||