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).
Comparison of wind velocity tests on Goshawk fans with different configurations and engine speeds.
| Identifier | ExFiles\Box 75\3\ scan0181 | |
| Date | 28th September 1922 guessed | |
| X4237 COMPARISON OF GOSHAWK FANS. Tests on S-Goshawk-11 car with original height of radiator - Wind velocity measured at 3 points - bonnet fitted during tests. Minus readings show when air is blown out from under bonnet. (Diagram showing 3 measurement points on a radiator representation, labeled 1, 2, 3) Handwritten notes: X4240, X4237 16" standard Fan and Pulley. | Engine revs. | 1st. position. | 2nd. position. | 3rd. position. | |--------------|----------------|----------------|----------------| | 500 | - 80 | 310 | 270 | | 1000 | - 450 | 760 | 640 | | 2000 | - 1250 | 1800 | 1550 | 18" Fan and large pulley. | 500 | - 150 | 390 | 220 | | 1000 | - 470 | 790 | 720 | | 2000 | - 1400 | 1800 | 1700 | 18" Fan and standard pulley. | 500 | - 200 | 400 | 360 | | 1000 | - 750 | 920 | 830 | | 2000 | - 1700 | 2340 | 2100 | 18" Fan and std. pulley with cowling. | 500 | 220 | 470 | 370 | | 1000 | 450 | 1000 | 910 | | 2000 | 910 | 2360 | 2320 | Large pulley, 18" blades, cowling. | 500 | 130 | 300 | 280 | | 1000 | 360 | 800 | 710 | | 2000 | 1000 | 1900 | 1500 | | ||