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).
Pre-ignition and mica insulation flaking issues with Bentley sparking plugs.
| Identifier | ExFiles\Box 58\2\ Scan290 | |
| Date | 10th February 1936 | |
| V6000 Hd.{Mr Hayward/Mr Huddy} From Hs{Lord Ernest Hives - Chair}/Wst. c. to H.{Arthur M. Hanbury - Head Complaints} c. to K.{Mr Kilner} Hs{Lord Ernest Hives - Chair}/Wst.3/MA.10.2.36. BENTLEY SPARKING PLUGS. With reference to your Hd{Mr Hayward/Mr Huddy}/SB.{Mr Bull/Mr Bannister}9/HR.6.2.36., with copy of H.7/H.5.2.36., attached. We have examined the plugs referred to and find that they exhibit the same characteristics as all other plugs of the 765A type which we have examined, i.e. pre-ignition due to the mica insulation flaking. We do not think that this failure is accelerated by the lead fuels. There is no doubt that the fitting of 850 plugs which have a washer type construction will cure the trouble and the sooner plugs are changed over in customers hands the better. The plugs in question have not been cleaned and if you are interested we can demonstrate to you the exact cause of the trouble. | ||