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).
Endurance test report for a lubricated grey fibre rubbing block.
| Identifier | WestWitteringFiles\K\July1923\ Scan46 | |
| Date | 27th April 1923 | |
| EFC. PB.91. April 27th 1923. ENDURANCE TEST OF LUBRICATED GREY FIBRE RUBBING BLOCK. The above test, which consisted of the equivalent of a 10,000 mile run, is now finished. The cam was given an initial smearing with oil, and the well at the base of the cam pillar filled with oil. Twice during the run, this well was filled but the oil leaked away. A spring exerting a pressure of 1 lb. on the points was used. The maximum wear on the rubbing block was found to be .005" i.e. from .260" to .255". N.B. In the previous test with an unlubricated grey fibre rubbing block, the wear for the same equivalent mileage was .008" and a good deal of fluffy material from the wear of the block was deposited all over the parts. Besides reducing the amount of wear on the fibre block, the oil has had the effect of damping down the fluffy particles worn away, so that they were simply deposited along the contact breaker lever and spring instead of flying about inside the distributor as occurred in the test with the cam dry. Attached is the lever with the block fitted. On this test standard irridio-platinum contact points were used, which gave no trouble. Upon examination at the end of the test, the contact point on the lever (negative) was seen to have a small platinum pip formed upon it, and a corresponding recess in the screw contact | ||