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 weight, compression, and permanent set measurements for a solid type piston.
| Identifier | ExFiles\Box 35\2\ scan 220 | |
| Date | 12th April 1920 guessed | |
| ② SOLID TYPE PISTON. X-2748 WEIGHT IN LBS. | COMPRESSION | PERMANENT SET 276 | .011 | Nil 286 | .011 | " 296 | .011 | " 306 | .0115 | " 316 | .012 | " 326 | .012 | " 336 | .0125 | " 346 | .0125 | " 356 | .013 | " 366 | .013 | " 376 | .013 | " 386 | .0135 | " 396 | .0135 | " 406 | .014 | " 416 | .014 | " 426 | .0145 | " 436 | .0145 | " 446 | .015 | " 456 466 476 486 496 506 516 526 (Faint background text: MOTOR INSTRUCTION) | ||