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).
Alteration of the Big Bore Bentley Head to standardize the compression ratio.
| Identifier | ExFiles\Box 82\4\ scan0206 | |
| Date | 20th December 1935 | |
| X200 To RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Smth.8/KW.20.12.35. Big Bore Bentley Head. The drawing EB.2560 provides for a compression ratio of 6.8 to 1. we propose to standardise 6.4/1. Will you please stop all castings going through the foundry so that modifications can be made. The alteration involves increasing the depth of the combustion chamber from 1.025 to 1.150, with the corresponding lowering of the bottom joint face of the head. E.{Mr Elliott - Chief Engineer} Dept. are altering the drawing accordingly. Hs{Lord Ernest Hives - Chair}/Smth. | ||