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 to Phantom III cylinder heads, including valve plating and spring retention.
| Identifier | ExFiles\Box 96\2\ scan0074 | |
| Date | 25th October 1935 | |
| x354 To RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}9/KW. 25.10.35. Phantom III. With regard to the cylinder heads which you are preparing for us to Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}3/KW.11.10.35 and Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}28/KW.15.10.35, we understand that the S/SLV. valves being fitted to A head will not take copper plating satisfactorily. Will you please chrome plate the stems instead, and maintain the clearance as requested of .001 - .0015" in the guides. The copper plating can be carried out on 3 of the KE exhaust valves on B side, giving a final diametrical clearance of .0015 - .002" in the guides. The remaining valves on this head are the latest standard with standard clearances. In several cases both on production and our own engines, the spring ring which retains the poppet valve return spring in the silent tappet mechanism has come adrift from the groove. Will you please incorporate the scheme Hs.{Lord Ernest Hives - Chair}2215 to retain the springs on the set of tappets which you are preparing in conjunction with the cylinder heads. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||