Noise testing results for modified contact breaker levers and various magnetos.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan174 | |
| Date | 1st February 1928 guessed | |
| -3- Contd. "In addition to the above, one of the suggested modified type of contact breaker lever was tried on each of two of the above machines in turn, in order to see if noisiness was affected by such change. No appreciable difference was observed." In this report magneto No.9802 referred to is not one of the present six, but one of the earlier ones which has been running on 9-EX. The modified type of contact breaker lever referred to is a type of lever with what we think is an improved method of holding the rubbing block. This is only a modification in what might be called the internal design of the lever and does not affect other things. The other two machines were tried out for noise by our Test Dept. and their report is as follows :- "We have now completed the test on the two magnetos of the above type (EW6) which you submitted to us. The first one No.100096 was unsatisfactory for noise, your assistant Mr.West I believe heard it on a chassis. Both the dist- ributor gears and contact breaker being very noisy. The second one No.105302 has been through dynamometer test and is fairly satisfactory, in fact it is quite comparable with the standard for noise which we have been passing. The make and break is the only noticeable feature on it. We should say that the make and break noise is more noticeable than the standard EO6 magneto, but taken all round it is, as before stated, a passable job." Of these six therefore, two are considered acceptable with regard to quietness. The remaining four we propose to return to Messrs. North at their suggestion for modification. These machines are not on the average as quiet as the Lucas machines which we have with similar electrical performance. We have demonstrated this to Mr. North apparently Contd. | ||
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).