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 condition of the crankshaft and bearings for chassis B.6.BN, including detailed measurements and repair recommendations.
| Identifier | ExFiles\Box 146\3\ scan0183 | |
| Date | 24th November 1936 | |
| To Bentley Motors (I93I) Ltd. DERBY copy to Hd.{Mr Hayward/Mr Huddy} Levallois re: Crankshaft and bearing wear etc.. Chassis B.6.BN{W.O. Bentley / Mr Barrington} - Mr. E.E. BLANC With further reference to your RmI7/MJ. 2.II.36 and Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}I8/JH.2.II.36, we have dismantled the engine of the above chassis, the car having covered a total mileage of 44750 Kms. and the following is our report upon the condition of the crankshaft and bearings : CRANKSHAFT : No.I No.2 No.3 No.4 No.5 No.6 No.7 Max. & Min. ( 2"2475 2"24775 2"248 2"2475 2"24775 2"247 2"247 diameter of ( 2"247 2"247 2"24725 2"24375 2"247 2"2465 2"2465 main journals ( Ovality: .0005 .00075 .00075 .00I .00075 .0005 .0005 Diameter of ( I"998 I"998 I"998 I"998 I"99775 --- --- crankpins ( Internal dia.( of the L.B. ( 2"00I 2"00I 2"00I 2"00I 2"00I --- --- bearings (Big ( ends). CONDITION OF MAIN BEARINGS (white metal):- Nos. 2,3,4,5 & 6 bearings are cracked and there is a certain loss of metal from them. CONDITION OF BIG END BEARINGS (lead bronze):- These bearings have covered 28050 kms. and show no signs of wear. No. 3,4 & 6 bearings have been lightly scored by small pieces of white metal which found their way into the oil circulation. The metal of one of the liners of n°. 4 big end will have to be replaced because the lead bronze has broken away in small pieces. CRANKPINS :- These are in an OK. condition and no wear has taken place since the fitting of the lead bronze bearings. MAIN JOURNALS OF CRANKSHAFT :- In view of the rather large amount of wear of the main journals, especially N°. 4, we think that it will be absolutely necessary to have the main journals re-ground. As we are not in a position to re-ground crankshafts ourselves, we have therefore, been in touch with several firms who undertake this sort of work, none of them however, undertake the nitruration (nitriding) of crankshafts, they all recommended Messrs. Aubert & Duval, the steel manufacturers, 62, avenue de la{L. A. Archer} République, Paris, as being the best firm for the above special class of work and in their opinion a firm which could give entire satisfaction. ..... | ||