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).
Modifications for a reinforced and thickened combustion chamber on the Wraith III and Bentley 111 cylinder heads.
| Identifier | ExFiles\Box 8\6\ 06-page42 | |
| Date | 19th September 1938 | |
| Handwritten: [Top Right] SWDL.{Len H. Swindell} What promise for D.A. details. DA.{Bernard Day - Chassis Design}c.19.9.38. 619 [Top Left] Liles [Attached routing slip, mostly crossed out] Mr/WC c. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/Sedl. c. RHD/VS{J. Vickers} Typed: WRAITH 111 - CYLINDER HEAD WITH REINFORCED COMBUSTION CHAMBER. Please receive herewith :- E.CD.905. Thickened Combustion Chamber - Wraith 111 and Bentley 111. The metal thickness around sides and top of combustion chamber has been made exactly the same as for the Bentley 11 cylinder head, also the webs joining the stud bosses to the combustion chamber wall have been reintroduced. Further, we have added a little extra metal at lower ends of exhaust ports to reduce the risk of steam pockets at these points which are adjacent to the valve seats. The reason for these changes is the cracks developing in the exhaust valve throats on one or two experimental engines. It will be necessary to alter the cylinder head cores, and this should be done immediately so that any further cylinder heads cast will include these alterations. Will you please detail and instruct immediately. DA.{Bernard Day - Chassis Design} | ||