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 the Spectre engine regarding an exhaust valve, camshaft timing, and the oil lubrication system.
| Identifier | ExFiles\Box 91\1\ scan0033 | |
| Date | 31th July 1935 | |
| To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell} 8300 Hs{Lord Ernest Hives - Chair}/Swd1.5/MJ.31.7.35. c. to Ey. SPECTRECodename for Phantom III. Since the failure of the exhaust valve in France, will you please delete the drilling of the lightening hole in the stem and instruct this modification. Will you also include the modification Hs.{Lord Ernest Hives - Chair}1768 which is an extra and alternative keyway in the camshaft to give a more selective valve timing. With regard to our previous trouble of dynamo pinion bush seizing, we have not as yet had any alternate scheme of lubrication other than the pressure feed taken from the low pressure relief valve, which was carried out experimentally. Will you please instruct this scheme for all units until such time that an alternative and satisfactory method has been tested. The first unit built by production and which we have had on test included the larger oil pump LeC.4400 in conjunction with the original relief valve LeC.3790. At high speeds the pressure was far too high and registering 80 lbs/sq.in. at 70°C. at 3500 RPM. Until the modified relief valve is fitted, the original pump/should be used. LOD.E.84791 Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||