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).
Schemes tested to prevent noise transmission through the dashboard thermometer.
| Identifier | ExFiles\Box 138\1\ scan0268 | |
| Date | 13th June 1936 | |
| X 1160 To E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Std.8/JH.13.6.36. Report on Schemes Tested for Preventing Noise Transmission Through Dashboard Thermometer. Two such schemes have been tested, one to Rm.{William Robotham - Chief Engineer} 80 and one to LeC. 5060. The latter scheme was designed to be used with existing thermometer stock, as the former necessitates a special bulb. Test :- Both schemes have been fitted to a Phantom III car (with noise insulation scheme fitted) and tested for tappet and valve spring noise at the worst speeds for this, 40-50 m.p.h. in second speed and 60-70 m.p.h. in third speed. The scheme Rm.{William Robotham - Chief Engineer} 80, as made using the packing piece Ex. 22101, was successful in reducing the noise until it was practically inaudible. This test was made on a Phantom III with automatic tappets out of action, and valve clearance set of .006". The same scheme is running on 32-EX in France, the valve spring noise etc. being inaudible on this car. (automatic tappets in action). The scheme LeC. 5060 was not tested exactly as made, the top rubber gland E.{Mr Elliott - Chief Engineer} 88231 being reduced in length by .060" in order to facilitate assembly. With this modification the scheme gave a fair success, being very much better for noise than the standard connection. It was improved still further by reducing the initial compression of the glands by .020" - .040". In this final state (i.e. total compression of glands reduced 0.100" from the design figure) This scheme is approximately as quiet as the first scheme Rm.{William Robotham - Chief Engineer} 80 | ||