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).
Technical memorandum discussing engine over-oiling, related sparking plug trouble, and tests on various scraper rings.
| Identifier | ExFiles\Box 72\1\ scan0142 | |
| Date | 10th May 1928 | |
| To R.{Sir Henry Royce} from HS{Lord Ernest Hives - Chair}/ACL. c. to E.J. Wor.{Arthur Wormald - General Works Manager} c. to R.G. E.{Mr Elliott - Chief Engineer} c. to B.Y. 48980 Hs{Lord Ernest Hives - Chair}/ACL/LG10.5.28. RR.F. - OVEROILING. X.2175 X.3996 X.3368 X.3980 The influence of the reduced oil leakage through the bearings, by employing grooveless bearings, has not been sufficient to enable us to use the scraper ring at the top of the skirt without encountering over-oiling troubles. We have tested various rings in the top position as stated in a previous report but up to the present have not met with any measure of success. We have tested 'L' section scraper rings but found them little different to the Perfect Circle ring. This we thought was probably due to the deep section - .185 - because when experimenting with the earlier Phantoms we found a deep section ring not such an efficient scraper as a narrow one. We however want to avoid the use of 'L' section rings if possible The overoiling problem is much more acute in the case of aero engines than with automobile engines due to the greater range of running conditions. We have to use cool running plugs due to the high M.E.P. and the long periods at which the engine is called upon to operate at high output and such plugs, if subjected to oil when light running, soon fail. A consider-able period is spent in light running when the engines are in service and it is during this period we have experienced most of our sparking plug trouble due to over-oiling. During tests on the Curtiss engine we found oil Contd. | ||