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).
Blueprint detailing modifications to the Spectre Piston, showing an additional sawcut and diametrical drop measurements.
| Identifier | ExFiles\Box 4\1\ 01-page102 | |
| Date | 1st January 1940 | |
| B.V. 42. ADDITIONAL SAWCUT ON PRESSURE SIDE TO SAME DIMENSIONS AS SAWCUT ON OPPOSITE SIDE 3.231 3.247 3.247 - 1/2 PRESSURE INSULATION 3.2475 - 1/2 3.2475 + 1/2 DIAGRAM OF DIAMETRICAL DROP AROUND PISTON CIRCUMFERENCE 45° OF GUD PIN Diametrical Drop Measurements (clockwise from left): .000, .0005, .0008, .0017, .0028, .004, .0051, .0063, .0071, .0077, .0082, .0077, .0071, .0063, .0051, .004, .0028, .0017, .0008, .0005, .000 MODIFICATION TO SPECTRECodename for Phantom III PISTON FOR ALL OTHER DIMENSIONS SEE E.84545/17 SCALE 1/1 W/D /40 | ||