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).
Recommendation to delete drain holes in silencers as they are a source of exhaust noise.
| Identifier | ExFiles\Box 6\7\ 07-page066 | |
| Date | 19th March 1930 | |
| To BY.{R.W. Bailey - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to Ds. Y5230 Ha/Rn.{Mr Robinson}1/WJ.19.3.30. DRAIN HOLES IN SILENCERS. Y7230. x5230 On a number of occasions recently, exhaust noises on the pick-up have been traced to these drain holes. On our experimental cars we almost invariably block these drain holes up and have run a big mileage without experiencing any trouble. We also do not think that they serve any useful purpose as they cannot deal with the condensation which takes place when the engine is started up, after a few moments running the silencer is dried up. However, since these holes are a source of trouble, we recommend that they should be deleted on both cars. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||