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).
Technical drawing of a Tappet with dimensions.
| Identifier | ExFiles\Box 126\2\ scan0142 | |
| Date | 18th November 1938 guessed | |
| TAPPET SS{S. Smith} 212 TAPPED HOLE 2 7/8" 9/32" 1 1/2" +.011 -.009 39/64" DIA 3/8" 1 1/2" 1 11/32" | ||