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).
Investigation into a carburetter popping issue on Chassis 3-DL-36 for Mrs Luck.
| Identifier | ExFiles\Box 131\2\ scan0206 | |
| Date | 20th June 1938 | |
| 1113 To Hs.{Lord Ernest Hives - Chair}. from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} c. By.{R.W. Bailey - Chief Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} c. Rm.{William Robotham - Chief Engineer} ------------------------ Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}2/N.20.6.38. Re: Chassis 3-DL-36 - Mrs Luck. --------------------------------- The car returned to Cricklewood with the complaint of popping in the carburetter at approximately 30 m.p.h. The diagnosis that valve sticking was the cause, has proved to be incorrect. The popping or blow back in the carburetter being so persistant at approximately 30 m.p.h. was the reason I very much suspected, and was other than valve trouble. The symptoms were very similar to the trouble we had in the early days with the 25/30 h.p. when plug trouble was the cause. This seems to be plug trouble but the cause apparently is due to sooty oily plugs causing a delayed firing. The trouble would appear to be caused by the over oiling of the engine combined with uneven distribution. After a discussion with BY.{R.W. Bailey - Chief Engineer} on the telephone, we verified that the cause was not due to the distributor being wrongly connected up. To try and cut out over oiling of plugs we fitted a new set of rockers, which had less flow of oil from the pad end. A carburetter which had been to the makers for mods, was fitted, trusting by this to obtain a slightly weaker mixture. The results although promising were not considered to be good enough. The trouble could be cured every time by the fitting of new or clean plugs. By fitting the carboned up plugs the blow back could be reproduced. Arrangements were therefore made between BY.{R.W. Bailey - Chief Engineer} and myself that the car should go up to the Works for further investigation. GWH.{George W. Hancock - Head Chateauroux} | ||