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 history and specifications of chilled cylinder bores for Bentley production.
| Identifier | ExFiles\Box 103\2\ scan0028 | |
| Date | 14th February 1939 | |
| To RM{William Robotham - Chief Engineer}/CTS{C. Trot Salt - Carburation} c.c. GWH{George W. Hancock - Head Chateauroux} (K) BY/NS.{Norman Scott}1/MG.14.2.39 BENTLEY PRODUCTION CHILLED CYLINDER BORES. We have looked into the history of the treatment of cylinder bores. Information is rather scant, but we give below our findings. The cylinder bores on all production Bentleys had chilled cores. Up to April 1937 they were lightly chilled, from April to June 1937 a heavier chill was used. After this time the bores were unchilled. The following chassis are the last that we can trace that have engines fitted with cylinder blocks cast with chilled bores. CHASSIS NO. ENGINE NO. SERIES B - 38-KT N. 4-BY 1st 100 in K B - 182-KT W. 7-BP 1st 100 in K B - 194-KT C. 4-BJ 1st 100 in K B - 1-KU U. 4-BR 2nd 100 in K From this we suggest that the chilled bores went off early in the second half of K.Series. In January 1937 the Phosphorous content was reduced from 4% to .25%. The following Brinell figures are given for reference: Brinell Figure Chilled bores .... 250 - 260 Heavy Chilled bores 260 - 270 Non-chilled ) 201 - 229 (.25% Phosphorous) [STAMP: FEB 15 A.M. 1939] BY/NS{Norman Scott} For Salt | ||