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).
Velocity tests in ft. per min. through a radiator with and without an 18' fan cowl.
| Identifier | ExFiles\Box 77\4\ scan0290 | |
| Date | 9th November 1922 | |
| Y4240 3.G.11. 9.11.22. VELOCITY TESTS IN FT. PER MIN. THROUGH RADIATOR. 18" FAN COWL OFF. POSITIONS. | 3rd. Gear. 20 m.p.h. | 2nd. gear. 10 m.p.h. | 1st. gear. 2 m.p.h. 1 | 740 | - 270 | - 460 2 | 1370 | 1070 | 900 3 | 1240 | 930 | 700 4 | 1480 | 750 | 600 5 | 2040 | 880 | 460 minus readings taken at half + value. 18" FAN COWL ON. 1 | 600 | 540 | 380 2 | 1300 | 1100 | 840 3 | 1160 | 960 | 680 4 | 1480 | 1160 | 640 5 | 2020 | 900 | 430 | ||