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).
Test report comparing the load lifting capabilities of various piston configurations.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan108 | |
| Date | 15th February 1926 guessed | |
| contd :- -3- TYPE OF PISTON. 1000 r.p.m. Load lifted by piston. Oil press: 13.5 lbs/sq.in. Temp. 60°C (1) Standard piston. Cup leather well worn and pliable. 15 lbs. (2) As (1) with a light ring to pack out cup leather. 27 lbs. (3) Standard piston. Tight new cup leather fitted. 35 lbs. (4) As (3) with a light ring fitted under the cup leather. 30 lbs. (5) XX All steel piston rings - no cup leather. Two rings 1/16" wide. 15 lbs. Method of applying load. The power from the relay also increases with increasing speed. This increase is about 20% when the speed is raised from 1000 to 1500 r.p.m. The exact reason for this is somewhat obscure as the oil pressure by the gauge does not rise proportionally. One can only conclude that the leakage past the small master piston necessitated by its clearance to prevent sticking contd :- | ||