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 on air leakage during compression on a standard Phantom engine, with results tabulated by RPM.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan057 | |
| Date | 12th October 1926 guessed | |
| contd :- -2- The amount of air used is measured by water replacement in a container having a calibrated gauge glass at the side. The action of the container is such that a small drop of pressure due to abstracting air results in its replacement by water which flows from a constant level tank situated at the top. The water has to be lifted less than a quarter of an inch and as this negative head remains constant we avoid all appreciable suction losses. A compression pressure gauge fitted to the cylinder shews the 'peak' pressure attained. We have carried out a test on the standard Phantom of 4.1 to 1 compression ratio to see what leakage occurred on compression. The water and oil was maintained at normal working temperature of 30°C and 60°C respectively. The following results shew how the leakage varies with engine speed :- | R.P.M. | Leakage cu.in/min. | Leakage cu.in/comp.stroke. | |---|---|---| | 500 | 184 | .368 | | 750 | 208.5 | .278 | | 1000 | 246 | .246 | | 1250 | 319 | .255 | | 1500 | 275 | .183 | | 1750 | 168.5 | .096 | | 2000 | 105 | .052 | contd :- | ||