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).
List of specifications for a tested cylinder head.
| Identifier | ExFiles\Box 124\2\ scan0279 | |
| Date | 17th December 1940 | |
| - 2 - Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}2/RH.{R. Hollingworth}17.12.40. The first cyl head tested on 3.B.50 was Exs.1383, sketch attached, which had the following specification (1) Local increase in throat area. (2) Graduating the increased throat Exs.1384. (3) Machining away the turbulent lip Exs.1758. (4) Clearance above the exhaust valve reduced. (5) Recessing the sparking plug to bring it nearer the combustion chamber, thus reducing the pocketing to Exs.1869. (6) .100" machined off the face, thus raising the compression ratio to 6:9:1 and 111 cc's capacity. (Continued) | ||