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).
Graph showing 'New Phantom' piston leakage versus compression pressure at two different engine speeds.
| Identifier | ExFiles\Box 66\1\ scan0118 | |
| Date | 2nd November 1926 | |
| "NEW PHANTOMCodename for PHANTOM I" PISTON LEAKAGE. SKETCH No 39 ENGINE No R.E. 25. (No 5 Cyl) STANDARD "L" SECTION RINGS. JACKET TEMPERATURE. = 75°C. OIL TEMPERATURE = 60°C. LEAKAGE IN CU. INS PER STROKE AT ATMOSPHERIC PRESSURE COMPRESSION PRESSURE (LBS / □") 500 R.P.M. 1000 R.P.M. HWB 2/11/26 | ||