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).
Comparative table of British, Continental, and American car engine specifications against the Goshawk model.
| Identifier | ExFiles\Box 42\2\ Scan061 | |
| Date | 16th March 1922 guessed | |
| British Cars. Make and model. No. of cyls. Bore and stroke. Piston displacement Cu.ins. % larger than Goshawk 11 Goshawk. 6 3 X 4 1/2 190.8 30 HP. Armstrong-Siddeley. 6 3 1/2 X 5 1/4 303.1 + 58.2% 20 HP. Austin. 4 3 3/4 X 5 220.9 + 15.0% 16 HP. Bentley. 4 3 1/8 X 5 1/8 180.2 - 5.5% 20 HP. Crossley. 4 3 1/2 X 5 1/8 226.1 + 18.4% 30 HP. Crossley. 4 4 X 5 1/2 276.5 + 45.3% 20 HP. Daimler. 4 3 1/2 X 5 1/8 197.2 + 3.6% 20 HP. Ruston Hornsby. 4 3 1/2 X 5 1/8 226.4 + 19.4% 25 HP. Straker Squire. 6 3 1/2 X 5 1/8 235.9 + 23.6% 16 HP. Sunbeam. 4 3 1/8 X 5 1/8 180.2 - 5.5% 24 HP. Sunbeam. 6 3 1/8 X 5 1/8 270.4 + 42.1% 36 HP. Talbot. 6 3 1/2 X 5 1/2 235.9 + 23.6% 25 HP. Vauxhall. 4 3 1/2 X 5 1/8 243.0 + 27.8% 30 HP. Vauxhall. 4 3 3/4 X 5 1/2 277.1 + 45.7% 20 HP. Wolseley. 6 3 1/8 X 5 1/8 235.9 + 23.6% Continental Cars. 16 HP. Delage. 4 3.15 X 5.91 184 - 3.1% 25 HP. Delage. 6 3.15 X 5.91 276 + 45.3% 20 HP. Delaunay-Belleville. 6 3.07 X 5.51 245 + 28.6% 16 HP. Lorraine-Dietrich. 6 2.95 X 5.12 209 + 10.0% 18 HP. Voisin. 4 3.74 X 5.51 242 + 27.3% 20 HP. Minerva. 4 3.5 X 5.5 217 + 14.2% 20 HP. Fiat. 6 2.95 X 5.12 210 + 10.5% American Cars. Buick (six) 6 3 3/8 X 4 1/2 241.6 + 26.8% Essex. 4 3 3/8 X 5 178.9 - 6.7% Ford. 4 3 3/4 X 4 176.7 - 6.7% Hudson (super-six) 6 3 1/2 X 5 288.6 + 51.1% Packard (single-six) 6 3 3/8 X 4 1/2 241.6 + 26.8% Studebaker(light-six) 6 3 3/8 X 4 1/2 207.1 + 8.1% | ||