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 Wellworthy Piston Rings discussing the testing of cylinder and piston ring material wear.
| Identifier | ExFiles\Box 148\3\ scan0385 | |
| Date | 31th August 1938 | |
| SERVICE DEPOTS LONDON 89 BLACKFRIARS RD. S.E.1 TELEPHONE: WATERLOO 5762/3 172 GT. PORTLAND ST.{Capt. P. R. Strong} W.1 TELEPHONE: MUSEUM 2433 119 LEYTONSTONE RD STRATFORD E.15 TELEPHONE: MARYLAND 2439 BIRMINGHAM 143 SUFFOLK STREET TELEPHONE: MIDLAND 0638 MANCHESTER 232 DEANSGATE TELEPHONE: BLACKFRIARS 5914 NEWCASTLE MILLICAN'S BUILDINGS, MARKET ST TELEPHONE: 23874 ON ADMIRALTY, WAR OFFICE AIR MINISTRY, INDIA OFFICE LISTS WELLWORTHY PISTON RINGS LIMITED PISTON & PISTON RING SPECIALISTS LYMINGTON HANTS WORKS & HEAD OFFICE: STANFORD RD SERVICE DEPOTS LIVERPOOL 45 RENSHAW ST.{Capt. P. R. Strong} TELEPHONE: ROYAL 5786 LEEDS 82 WOODHOUSE LANE TELEPHONE: 25774 CROYDON 246 HIGH STREET TELEPHONE: 0234 SOUTHAMPTON 17 PORTSWOOD ROAD TELEPHONE: 74778 HULL 285 ANLABY ROAD TELEPHONE: 15312 CANTERBURY 21 & 22 ROSE LANE TELEPHONE: CANTERBURY 2456 TELEPHONE: LYMINGTON 520 (5 LINES) TELEGRAMS: WELLWORTHY CODE: MARCONI 1256? DIRECTORS: G.{Mr Griffiths - Chief Accountant / Mr Gnapp} H.{Arthur M. Hanbury - Head Complaints} ALEXANDER J.{Mr Johnson W.M.} W. HOWLETT C. B. KAY P. WALDEN OUR REF FB/AS. YOUR REF file (Cylinder bore wear) 31st August, 1938. Messrs. Rolls-Royce Limited, Derby. Dear Sirs, We thank you very much for your letter of the 25th enclosing print No.HR.638, which shows dies and peg for testing wear value of both cylinder iron and piston ring material. We are in agreement with your form of test and presume that you will load the peg when in contact with the disc with weights equivalent to a ring exerting its normal pressure in lbs per square inch as manufactured, which in our opinion will give relative wear value of Slotted Scraper and certain other types of Scraper rings, which are far removed from the combustion chamber, and practically unaffected by gas pressure, and that the other pressure used to test such specimens will be pressure approximating to maximum pressure development during combustion, and that you will therefore gain some valuable information. There is however, one point which we think had better be cleared up before we undertake to make or supply the material for the pegs. It is noticed that the peg diameter is given as .750" and it would not be possible to produce a peg of this diameter to a length of 1½". If we take a ring of approximately 3½" diameter which is very similar to rings used on a Bentley car then the radial thickness of a centrifugally cast pot for this particular ring would be slightly under 1/4". You could therefore not obtain the length 1.1/2" which is shown on your blue print. If on the other hand you had in mind, cutting a strip from the pot and using the length-wise dimension to get 1½" then the diameter, according to the radial thickness of the pot could not be more than 1/4". This, of course, would be the wrong | ||