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).
Letter discussing potential causes for main bearing scoring and wear on a Bentley 4 1/4 engine, chassis B.64.KT.
| Identifier | ExFiles\Box 146\5\ scan0023 | |
| Date | 24th October 1938 | |
| To Bentley Motors Ltd. Derby................Rm.{William Robotham - Chief Engineer} Copy to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} " " By.{R.W. Bailey - Chief Engineer} 1245 Sr is absent Levallois VA.6/HB.{C. E. Harcombe}24.10.38 re: Chassis B.64.KT - Mr. R.{Sir Henry Royce} FAYE /MH.{M. Huckerby}21.10.38 With reference to Rm{William Robotham - Chief Engineer}/Swdl{Len H. Swindell} we confirm that the main bearing which we sent to you for analysis is in connection with the job as per Owner's Complaint Report N° P-117. We think that you will probably remember when you visited Rue Gide at the commencement of last July, we showed you the crankshaft of the above car and you expressed surprise like ourselves as to the very pronounced scoring which had taken place on the main journals (apart from wear and ovality). It has always been somewhat of a puzzle to us why the main journals on certain Bentley 4 1/4 engines should badly score, wear and ovalize after a comparatively short mileage and it will really be of interest to us to know the cause providing it has now been established. Is it due to the following or a combination of all: 1°- Nitriding incorrect 2°- Bearing material 3°- Cleanliness of the crankshaft after the nitriding process. 4°- Insufficient filtering of the oil. VA.Vd | ||