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).
Modifications and fitting instructions for Bentley Main Bearings on the 4 1/4 litre chassis.
| Identifier | ExFiles\Box 115\3\ scan0166 | |
| Date | 5th January 1938 | |
| Swdl{Len H. Swindell} See me Rm{William Robotham - Chief Engineer} Voles (handwritten) To By.. (crossed out) from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} c. to Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}3/N.5.1.38. 1620 (handwritten) Re: Bentley Main Bearings. Kingsbury have received a memo re the above from Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}4/HR.23.12.37. with regard to the change-over to white metal on No.7. rear thrust bearing for 4 1/4 litre chassis. Attached to the memo is one from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}13/WH. 19.11.37 giving fitting instructions. This has been handed over to me with Kingsbury's remarks, which I am in agreement with. Kingsbury's remarks are:- " I notice that in the paragraph dealing with the AC.7 main bearings he (Swdl{Len H. Swindell}) mentions in paragraph A - Interference fit of .001" and in paragraph B - Bearing nip of .001" I am of the opinion that in so far as Depots are concerned, paragraph A should be deleted, as this obviously applies only to new work, and that paragraph B. should be amended so that the nip figure should be .002" at each side instead of .001" PK/KC. In the first place the sending of these memos to Depots should not be allowed without first your signature, secondly to what series of cars they are intended for. In this case if the instructions were carried out to existing cars, there would be repeated failures of bearings. It would mean that six months of valuable experience would be of no value. It has been definately established that with the previous drawing allowances of bearing shells and limits in the housings, bearings have been loose in their housings, before the car has left the Coachbuilders, and small mileages have been run before thump has appeared. We are of the opinion that even with new cars .002" nip would not be excessive. The point however, is to have the memo sent out corrected. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||