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).
Report page discussing crankshaft oil leaks and methods to tackle piston over-oiling.
| Identifier | ExFiles\Box 16\1\ Scan082 | |
| Date | 7th April 1915 guessed | |
| -2- centrifugal force at all. When we refer to the crankshaft of our engine we see the analogy is not quite correct because there is a possibility of leak from the passage C, and of course if this leak is serious then the centrifugal action makes the oil prefer to leave by the leak at C rather than continue down the passage B. In the Experimental Shop we actually took tests of the pressure of oil in the two passages A and B and we found that even with a moderate leak at C there was no appreciable difference of pressure in the two passages, thus showing that the objection is rather theoretical than actual. Mr Hives states that the over-oiling trouble can be most successfully tackled by reducing the clearance at the bottom or skirt of the piston, that is to say, the diameter at the bottom or mouth of the piston should be increased by peening with a hammer, or if this is not [handwritten note: by tinning a band on M.L. Olley] possible by running a ring or band of [handwritten note: white metal about 1/4" wide] round. The clearance should be reduced to about .001". We have never had any trouble from a [handwritten and struck-through: through] piston seizing at this point, therefore the | ||