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. regarding the behaviour and supply of new heat-formed high poundage compression rings for an experimental engine.
| Identifier | ExFiles\Box 148\3\ scan0304 | |
| Date | 25th January 1938 | |
| TELEPHONE: VICTORIA 0671 (5 LINES). CODES: A.B.C. 5TH EDITION. ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY. ON ADMIRALTY, WAR OFFICE AND AIR MINISTRY LISTS. THE LIGHT PRODUCTION CO. LTD. PROPRIETORS OF THE LONDON PISTON RING CO. LIMITED. TELEGRAMS: INLAND: NAPOLEONIC, SOWEST, LONDON. FOREIGN: NAPOLEONIC, LONDON. CHAIRMAN & MANAGING DIRECTOR: M.V. ROBERTS. DIRECTORS: E.G. DAVIES, WM. THISTLE. ENGINEERS 60/66, ROCHESTER ROW, WESTMINSTER, S.W.1 WORKS AND GOODS ADDRESS: 61/67, GREENCOAT PLACE, WESTMINSTER, S.W.1. OUR REF. CHB/IR YOUR REF. 1020 or 1020a? 25th January 1938. Messrs. Rolls Royce Ltd., Experimental Dept., DERBY. Dear Sirs, For the attention of Mr.Matthews. On the occasion of the writer's last visit, we had some discussion concerning the behaviour of the high poundage Compression Rings which we supplied to you for your 3½" bore experimental engine, and you handed the writer a ring on which the gap movement had been excessive when fitting to a piston. We have since done some work on the relationship between the free gap and the extra radial thickness above B.E.S.A. which is called for on these rings, and it would appear that the free gap as originally made, was small for the thickness. Under separate cover, we are now posting to you 14 rings which have been heat formed to a somewhat larger free gap, the result being that the rings will withstand fitting to pistons and closing in a cylinder without departure from the normal free gap. You will find that, on fitting these to pistons, a slight increase in gap takes place, but on closing in a gauge or cylinder, the gap is restored. | ||