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).
Data table showing coefficients of discharge for Head 1, cross-referencing bore length with bore diameter.
| Identifier | ExFiles\Box 36\1\ scan 059 | |
| Date | 9th January 1917 | |
| -4- (b) COEFFICIENTS OF DISCHARGE FOR HEAD 1. | Length of Bore. | ½" | ¾" | 1¼" | 2" | 2¾" | 3½" | 4½" | |---|---|---|---|---|---|---|---| | Diameter of bore. 3/64" { R.in | .83 | .72 | .68 | .60 | X | X | X | } A | { R.out | .81 | .72 | .66 | .60 | X | X | X | | 3/32" { R.in. | X | .875 | .83 | .80 | .77 | X | X | } B | { R.out | X | .83 | .815 | .77 | .70 | X | X | | ⅛" { R.in. | X | X | .935 | .90 | .85 | .79 | X | } C | { R.out | X | X | .85 | .785 | .77 | .77 | X | | 3/16" { R.in | X | X | X | .89 | .865 | .84 | .82 | } D | { R.out | X | X | X | .845 | .83 | .80 | .79. | (upside down text at bottom): R.R. 386 A (170 H.{Arthur M. Hanbury - Head Complaints}(S.D) 142. (9-1-17) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1968 | ||