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).
The trial results of non-stellited Thompson-Products exhaust valves and requesting further information.
| Identifier | ExFiles\Box 158\4\ scan0195 | |
| Date | 2nd December 1937 | |
| To RHC.{R. H. Coverley - Production Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} Y 1360 Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/AP.2.12.37. THOMPSON-PRODUCTS EXHAUST VALVES. Herewith information on the first batch of Sil XCR. (non stellited) exhaust valves which you received personally for trial from Mr.Colwell of Thompson Products, Inc. Other than the results obtained, there is quite a lot of information we should like to obtain in respect of exhaust valves if this is possible when you reply to the above people. The valve we send you is one of the batch as described in the opening paragraph of this memo. It has run approximately 10 hours under full throttle conditions on Ethyl full and at an approximate temperature of 780°C. at the head of the valve, as observed with an optical pyrometer through the exhaust port. The seat as will be observed is rolling over into the form of a radius, the seat in the cylinder head being like-wise. This effect has taken up the valve clearance by approximately .005. The seat is beginning to get pitted and burnt and it does appear that we should not find this type of valve with an 'unstellited' seat sufficiently satisfactory under our conditions. One of our standard KE.965 exhaust valves with a stellited seat running in the next cylinder was in a very good condition. In other respects, however, the American valve appears quite satisfactory as far as we have gone and the acid test shows it to be free from cracks etc. We note in the latest batch of valves in accordance with the attached letter, that the last 8, part number B.151, are of similar material to the one we return but with stellited seats. As yet, we have had no opportunity of doing so and would really like more detail information on these valves before testing them. Detail information would consist of the following:- (1) What are the comparative merits of the materials sent, also the analysis and the comparative cost figures.? At the moment we are in the dark as to what all the symbols mean, that is Sil.XCR. Sil.XB., Sil.X8 head with a welded stem etc. continued | ||