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).
Diagram showing the ovality of a piston contour for modified grinding.
| Identifier | ExFiles\Box 87\2\ scan0027 | |
| Date | 18th March 1936 | |
| [ "B.V.81.", ".000", ".00012", ".00048", ".0011", ".002", ".003", ".0041", ".005", ".0059", ".0066", ".007", "45°", "¢ OF GUD. PIN", "DIAGRAM OF OVALITY OF", "PISTON CONTOUR", "MODIFIED GRINDING FOR B.V.42 PISTONS (SPECTRECodename for Phantom III)", "R.He", "18-3-36" ], | ||