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).
Table of average coefficients of discharge for various bore lengths and diameters.
| Identifier | ExFiles\Box 36\1\ scan 062 | |
| Date | 9th February 1917 | |
| -Y- (c) TABLE OF COEFFICIENTS OF DISCHARGE (average). Length of Bore:- Dia. of bore. | | ½" | ¾" | 1¼" | 2" | 2¾" | 3½" | 4½" | |---|---|---|---|---|---|---|---| | 3/64" { R.{Sir Henry Royce} in | .82 | .74 | .67 | .59 | X | X | X | } A | R.{Sir Henry Royce} out | .80 | .73 | .65 | .59 | X | X | X | | 3/32" { R.{Sir Henry Royce} in | X | .87 | .84 | .80 | .77 | X | X | } B | R.{Sir Henry Royce} out | X | .83 | .82 | .79 | .70 | X | X | | 1/8" { R.{Sir Henry Royce} in | X | X | .91 | .86 | .835 | .76 | X | } C | R.{Sir Henry Royce} out | X | X | .85 | .785 | .76 | .75 | X | | 3/16" { R.{Sir Henry Royce} in | X | X | X | .89 | .85 | .83 | .825 | } D | R.{Sir Henry Royce} out | X | X | X | .84 | .82 | .81 | .79 | (upside down text at bottom) R.R. 253 A (770 H) S.D. 442. 9-2-17. 1G 1905 | ||