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).
Dimensional changes to channel scraper rings to resolve an overoiling problem on Phantom II and 20/25HP chassis.
| Identifier | ExFiles\Box 16\1\ Scan117 | |
| Date | 7th January 1931 | |
| x740 By c` Hs.{Lord Ernest Hives - Chair} c` Wks. c` Secty from Mr. Mx{John H Maddocks - Chief Proving Officer}12/T7.1.31. OVEROILING re Phantom II and 20/25HP. We experience trouble with overoiling on both Phantom II and 20/25HP Chassis, more particularly on the latter. Some time ago I discussed the question with both you and the Experimental Dept. and suggested that we should increasedthe groove and correspondingly reduce the lands on the channel scraper ring. This has been done on a number of engines of both types, where we have experienced trouble, and also a number of engines have been built by the Works with rings to this altered dimension. We are now in a position to recommend that all rings be modifiedbefore any further engines are built up. RECEIVED JAN 1931 The suggested dimensions are as below:- Left Diagram: .085 ± 2 .015/-.10 RAD .0315 ± 2 ALL OTHER DIMENSIONS SEE DRG E55502 Right Diagram: .085 ± 2 .025/-.10 RAD .044 ± 2 ALL OTHER DIMENSIONS SEE DRG E76880 Mx{John H Maddocks - Chief Proving Officer} | ||