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).
Cylinder bore wear, comparing Brinell hardness values, and considering alternative castings to improve quality.
| Identifier | ExFiles\Box 86\1\ scan0243 | |
| Date | 29th May 1937 | |
| -2- to show that the brinell we are trying for, which is round about 250-270, will give us appreciably better wearing qualities than the normal brinell round about 200, which is being used by the Americans and the Midland Cylinder Co. For months past, we have been carefully collecting measurements of cylinder bore wear from Service Stations, and the figures so obtained with our present cylinder iron give us very average results, in fact, no better than we are getting on the Chevrolet which we are running about Derby. Taking a purely impartial view of the information available, we find it difficult to justify the bill of £1,500 to £2,000 a year which we are incurring in an endeavour to work to 250 brinell on our cylinder blocks, and consider that it is only reasonable to try some Midland Cylinder Castings, and some of our own castings without chills, in production forthwith. We are, therefore, circulating a standardisation sheet. Rm.{William Robotham - Chief Engineer} | ||