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 from The Light Production Co. Ltd. discussing modifications to a piston ring design, specifically trying an 'L' section ring.
| Identifier | ExFiles\Box 148\1\ scan0217 | |
| Date | 11th December 1939 | |
| 1256 File. TELEPHONE: VICTORIA 0671 (5 LINES). ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY. ON ADMIRALTY, WAR OFFICE AND AIR MINISTRY LISTS. CODES: A.B.C. 5TH EDITION. THE LIGHT PRODUCTION CO. LTD. PROPRIETORS OF THE LONDON PISTON RING CO. LIMITED. ENGINEERS CHAIRMAN & MANAGING DIRECTOR: M.V. ROBERTS. DIRECTORS: E.G. DAVIES. WM. THIRTLE. TELEGRAMS: INLAND, NAPOLEONIC, SOWEST, LONDON. FOREIGN, NAPOLEONIC, LONDON. 60/66, ROCHESTER ROW, WESTMINSTER, S.W.1 WORKS AND GOODS ADDRESS: 61/67, GREENCOAT PLACE, WESTMINSTER, S.W.1. OUR REF. CHB/DP 11th December, 1939. YOUR REF. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}1/MH.{M. Huckerby} Messrs. Rolls Royce Ltd., Experimental Dept., DERBY. RECEIVED 13 DEC 1939 HPS{Horace Percy Smith - Experimental Factory Mgr} For the attention of Mr. C.T. Salt. Dear Sirs, In reply to your letter of the 4th instant reference as above, we have been considering the suggestion you make to try an "L" section ring in place of the usual Scraper Ring. This will, as you suggest, necessitate the heat break saw cut position being altered, and in order to utilise it as a return oil passage it must, as we see it, be placed below the oil ring groove instead of at the back of it as at present. This will restore its position to the one it occupied on our original design, but there would be no necessity for the drilled holes in the ring groove, so that the weakness caused by one of these holes being immediately above that at the end of each saw cut would be avoided. We are not at all sure that the oil control will be as effective, but we cannot be dogmatic on this point because our experience is very definitely that one engine reacts to a modification very differently from another to the same modification. We would suggest therefore that an "L" section ring of 1/8" in width be tried with the heat break saw cut situated in the centre of a chamfer running from the underside of the lower ring groove to the piston skirt. We have found this arrangement to be more effective in returning the oil collected NATIONAL SCHEME FOR DISABLED MEN | ||