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).
'all out' tests detailing issues with fan belts, and performance tests on spark plugs and silencers.
| Identifier | ExFiles\Box 149a\2\ scan0032 | |
| Date | 2nd July 1932 | |
| -4- Fan. During the 'all out' tests considerable trouble was experienced with fan belts, (three in all were broken) it was found that some of the trouble was due to the fan pulleys being out of alignment, but even after this was corrected a further belt was broken. Tests were carried out with and without the fan at 30 M.P.H. and 'all out'; no difference at all in temperature was recorded in the 'all out' tests, and only one degree increase at 30 M.P.H. A further point noticed and proved by several tests was that the lap speed is increased by slightly over 1 M.P.H., when the fan belt is removed; this is not surprising when the temperature to which the belt rises during prolonged all out running is realised; it is almost impossible to hold ones hand on the belt after three or four laps at 74 M.P.H. Plugs. During all these tests Lodge K-14 (14 mm) plugs were fitted and behaved very well, there was no sign of any misfires at any speed and preignition was entirely absent. The compression ratio of the engine was higher than standard, 5.9:1, the increase being due to the use of a thin nickel alloy gasket (submitted as a sample for test). This gasket has given no trouble. Silencers. Tests were carried out to ascertain the improved performance gained by using the resonance silencer which we have produced experimentally as compared with the standard system. The average of several tests gives the following:- Lap Speed - Standard Silencer - 72.9 M.P.H. " - Resonance Silencer - 74.2 M.P.H. Increase - 1.3 M.P.H. | ||