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).
Instructions to correct the compression ratio of a Phantom II high compression cylinder head by machining the joint face.
| Identifier | ExFiles\Box 14\3\ Scan090 | |
| Date | 15th November 1933 | |
| x7050 To RHC{R. H. Coverley - Production Engineer}, from Hs{Lord Ernest Hives - Chair}/Std, Hs{Lord Ernest Hives - Chair}/Std.9/KT.15.11.33. P.II. HIGH COMPRESSION CYLINDER HEAD ( 6 : 1 ). We send you herewith the P.II. high compression ratio (6 : 1) head to Hs.{Lord Ernest Hives - Chair}1012, which we received from you recently, to have the combustion chamber volume corrected. The compression ratio at present is 5.8 : 1 instead of 6 : 1 owing to a D.O error. We require to have 0.100" machined off joint face - this should give us the required ratio. We should like this alteration at the earliest possible moment, as we wish to try this head in a car on the road before the design office finish detailing a similar one for the Vulture engine. On no account should the metal thickness at the face be reduced below 0.125" - if this thickness is reached before .100" is removed, no more metal must be removed. Hs{Lord Ernest Hives - Chair}/Std. | ||