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).
Graph plotting piston inertia torque for various engine cylinder configurations over a 360-degree cycle.
| Identifier | ExFiles\Box 127\3\ scan0268 | |
| Date | 25th November 1938 guessed | |
| PISTON INERTIA TORQUE RD. OF COUPLE ACC 10° 2.5° ω²r ω²l ω 3000 R.P.M. 1 CYL. TWICE FULL SIZE. 6 CYL. 12 CYL. 90° 4 CYL 12 CYL 45° STR 8 CYL OR 12 CYL. 60° 1" = 82 LBS. FT. FOR RECIPROCATING MASS OF 1LB PER CYL. 0 90 180 270 360 | ||