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).
Substitution of tappet guides with cast iron for cost-saving purposes on the Phantom III engine.
| Identifier | ExFiles\Box 148\5\ scan0158 | |
| Date | 26th April 1937 | |
| Copy to [Redacted] 1260 E/PEN.2/H.26.4.37. TAPPET GUIDES - P.III. The tappet guides on the P.III. are case-hardened and cost 4.7/- each. as the main side thrust on the tappet is taken by the tappet block which is in aluminium, we consider that the much lighter duty which the tappet guide has to perform in keeping the tappet square and guiding the upper end could satisfactorily be performed by a cast iron guide. The substitution of cast iron would result in a total saving of about 30%, largely owing to the reduction in machining operations. as there are 24 such guides per engine, the saving would be over £2.10.0. per chassis. The minor modifications necessary to the guide and tappet block are shown in RS.{Sir Henry Royce's Secretary}518 and RS.{Sir Henry Royce's Secretary}519 two prints off each of which we send you herewith. We understand that Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} is arranging for a set of valve gear incorporating solid rockers and the modified clamping on the tappet block to go on a 10,000 miles test. We should be pleased if you could manage to get these cast iron guides on to the same engine, as we should like to get these parts standardized, as soon as possible, as the saving is so considerable. Now that the tappets are working satisfactorily, we wish to try a number of alternatives for reducing cost, but as these will require more testing they can follow on and instructions will be issued later. E/PEN. Att: RS.{Sir Henry Royce's Secretary}518 and RS.{Sir Henry Royce's Secretary}519. | ||