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).
Flatness error discovered during testing of Bentley cylinder heads.
| Identifier | ExFiles\Box 103\2\ scan0110 | |
| Date | 24th March 1937 | |
| Copy. BY C. to RHC.{R. H. Coverley - Production Engineer} RHC{R. H. Coverley - Production Engineer}/EG.1/DB.{Donald Bastow - Suspensions}24.3.37. Re: Bentley Cylinder Heads. We have tested a number of Bentley heads and Cylinder Blocks and find a general error of approximately .003" out of flat. This error has always existed and we cannot produce them much better without lapping. The edge of joint face falls away as shown on sketch on Kingsbury's memo' to the extent of approximately .0015" to .002" for an extent of approximately .500" inwards from outer edge, due to action of grinding on leaving the metal of head. We are trying to improve upon our present standard. I have had a head pulled down on a block and the two come together except at edge as aforementioned. No distortion of cylinder bores could be detected. RHC{R. H. Coverley - Production Engineer}/E.Goodall. | ||