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).
Test report on Goshawk fan belt slip and radiator airflow speeds at varying levels of belt tightness.
| Identifier | ExFiles\Box 77\4\ scan0220 | |
| Date | 1st June 1923 | |
| X4240 To R.{Sir Henry Royce} Frontis. c. to D.{John DeLooze - Company Secretary} c. to Dr. c. to E.{Mr Elliott - Chief Engineer} c. to Hy.{Tom Haldenby - Plant Engineer} Hsd/T1.6.23. GOSHAWK. II - COOLING. X4751 X4040 X766 We have measured the slip of the Goshawk fan belt. We had the engine running on the bench fitted with the fan but with no radiator in front so that we could count the revs. of the fan compared with the revs of the crankshaft. The following is a test taken with a reasonably tight fan belt and a slack fan belt :- Engine REVS. | Fan revs. Belt tight. | Belt slack. 1000 | 1300 | 1170 2000 | 2300 | 1920 3000 | 2900 | 2280 We have also taken a test with the radiator fitted in front measuring the difference of the speed of air through the radiator with different degrees of belt tightness. The following is the result :- Degrees of Belt tightness. | Air speed through radiator. 1000 R.P.M. | 2000 R.P.M. 1 belt tight. | 370 ft. per min. | 750 ft per min. 2 | 360 | 750 3 | 370 | 740 4 | 370 | 590 5 | 370 | 590 6 belt slack. | 220 | 460 Contd. | ||