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).
The investigation and diagnosis of engine misfires on a customer's car.
| Identifier | ExFiles\Box 162\3\ img115 | |
| Date | 6th May 1938 | |
| To SG.{Arthur F. Sidgreaves - MD} c. to HS.{Lord Ernest Hives - Chair} c. to By.{R.W. Bailey - Chief Engineer} c. to RM{William Robotham - Chief Engineer}/RC.{R. Childs} MISFIRES ON Sg{Arthur F. Sidgreaves - MD}'s CAR. On arrival in London, Kennett informed me that he had changed a plug in No.6. cylinder the previous day because the engine was missing while running light in the garage. We tried the car as it was, and could not obtain any misfires, the idling was good, very little movement being felt in the car even running top gear 6 M.P.H. Inspection of the plug of which complaint was made showed a thin film of oil and rather more carbon than one would expect in 792 miles running. We replaced the offending plug, but could not reproduce misfiring on pick up, and the idling was still good. We then tried the plugs which had been to the works. These also gave good idling and slow running, but an occasional misfire was experienced on the get away after running slow some distance at 6 M.P.H. This could not be reproduced at will. Examination of the plugs after 10 mins. idling showed No. 5 & 6 had a slight film of oil, the rest being dry. We checked up on the distributor points, these were in good condition and the tappet clearances correct. We then fitted the Delco coil and again tried the car. This time we could not produce a misfire on pick-up after slow running. Kennett drove the car and expressed his satisfaction with the performance. The engine shows no signs through the exhaust of excessive oil, and according to the log 11 pts. of oil have been added in 3285 miles, giving an oil consumption of 2384 m.p.g. but we suspect a slight overoiling of No.6 cyl. under London Traffic condition, and this is most probably the cause of the misfire. Cont'd.{John DeLooze - Company Secretary} | ||