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).
Carburetter noise issues and proposing using the crankcase as a silencer.
| Identifier | Morton\M19\ img005 | |
| Date | 20th December 1930 | |
| ORIGINAL: TWIN CARBS To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c.c. to Sd. Wox. c.c. to Da.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c.c. to Ry. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}1/MJ.20.12.30. X.7080. X.5080. CARBURETTER NOISES. we now have the twin carburetters running. Naturally, in view of Hs{Lord Ernest Hives - Chair}'s criticism of the Phantom II we are most anxious to get these into a state where they can be standardised. The great disadvantage at present is the noise which is still quite excessive with the silencer provided. You will see from ACL's report of his visit to the Paris Show that Hispano's use their crankcase as a carburetter silencer presumably having a flame damper to prevent any possibility of blow back. We feel that this is likely to be one of the only means of silencing the twin carburetter without excessive loss of power. We think that if we have to lose 4 HP. to silence the single throat carburetter that it would pay us to utilise the crankcase even in this case. The scheme has several other advantages such as causing a depression in the crankcase and so reducing oil leaks, also providing upper cylinder lubrication. If you approve of the arrangement we should very much like a scheme for the 40/50 and the new 25 HP. Since it is standardised on several French cars and works well we cannot forsee any serious difficulties. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||