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).
Technical memo regarding a complaint of erratic pinking on a 4¼-litre chassis, identified as being caused by sooted spark plugs.
| Identifier | ExFiles\Box 90\2\ scan0158 | |
| Date | 21th May 1937 | |
| COPY. K/S. Sg.{Arthur F. Sidgreaves - MD} Pk21.5.37. 4¼-litre Chassis No. B.34.GA. Professor Dodds. Sg{Arthur F. Sidgreaves - MD}24/E20.5.37. This car was last in on the 14th inst. with a complaint of erratic pinking. This trouble was due to the plugs requiring cleaning owing to sooting up and it disappears directly the cleaning has been effected. The impression we get is that the engine is allowed to run too long with the mixture control in the rich or partly rich position. If our surmise is right, nothing would be gained by retarding the ignition, the setting at present being standard. (Sgd.) Pk. | ||