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).
Letter discussing cracked Sil.XCR valves and seeking feedback on the manufacturing issue.
| Identifier | ExFiles\Box 158\4\ scan0186 | |
| Date | 28th October 1937 guessed | |
| -2- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}1/MH.{M. Huckerby} Unfortunately we did not crack test these Sil.XCR valves before they ran, but assume that these cracks were in at this time as four of the same batch which have not been run reveal cracks, No.1 being one of the four. In view of this it is therefore, amazing that the valves did not completely fail whilst in the engine, the fact that they are cracked, however, makes us scared of continuing our tests on them. No.3. Valve with Stellited Seat. This valve is one of a set which you supplied to us over a year ago and which we remember as Sil.X. Since being fitted to one of our experimental chassis, this set of Sil.X valves have covered 35,000 miles, and the one we send you is representative of the whole set, being free from any cracks. During the last week we have received several more sets of Sil.XCR valves from Thompsons through our Mr.Coverley, and these are completely free from cracks. It is therefore assumed that the method of manufacture has been altered in comparison to the original set of Sil.XCR valves which you supplied to us and which have cracked. We should be pleased to hear from you regarding your views on these cracked valves. To us it appears to be characteristic of some forging trouble developed during the manufacture of this particular set of valves. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||