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 drawing for a half-size 'Valve D' component with three dimensioned views.
| Identifier | ExFiles\Box 170\2\ img028 | |
| Date | 2nd February 1921 | |
| 1650J - 37" Spring 1/2 size. Valve 'D', +90°, 7" B.R.A., 2/2/21, T.G.A., 2, 4, 7, 30, 60, 250 | ||