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).
Conference summary discussing the causes and potential solutions for piston rattles in engines.
| Identifier | ExFiles\Box 76\4\ scan0186 | |
| Date | 22th March 1920 | |
| X.1434 To CJ. from Bn.{W.O. Bentley / Mr Barrington} To R.{Sir Henry Royce} from Bn.{W.O. Bentley / Mr Barrington} X.2748. re PISTON RATTLES. X.3751. Bn{W.O. Bentley / Mr Barrington}1/W22.3.20. c. to Wor.{Arthur Wormald - General Works Manager} c. to By.{R.W. Bailey - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to Sft.{Mr Swift} c. to Da.{Bernard Day - Chassis Design} c. to EFC. c. to EP.{G. Eric Platford - Chief Quality Engineer} X.1434 In accordance with your instructions a Con- ference was held this morning at which Wor{Arthur Wormald - General Works Manager}, Aft, Da{Bernard Day - Chassis Design}, Hs{Lord Ernest Hives - Chair}, EP{G. Eric Platford - Chief Quality Engineer}, By, and Bn.{W.O. Bentley / Mr Barrington} were present. The following is a summary of the relevant information concerning piston rattles which is at present available and which was reported to the Conference:- Piston rattles are believed to be caused by the binding of the top band of the piston when the engine is run with the piston in a carboned up state, full out at high speeds. They cannot be ob- tained in new chassis in which the pistons are not carboned up, and have occurred after 5 or 6 thousand miles if when Castrol is used for the engine. They entirely disappear if the engine is decarbonised. Piston rattles have been observed on 7-CA the Bench Test Engine, 2.EX, and slightly on 49-GB In all cases, with the exception of 7-CA Castrol has been used as engine lubricant. We are awaiting in- formation from France to confirm that nothing but Castrol has been used as engine lubricant in 2.EX while in France. In the case of 7-CA the clearance on the top band was not standard but considerably finer than at present in use. Considerable experience of cars which have run many thousands of miles but not using Castrol, is now available, and no cases of piston rattles have occurred. For example, Mr. de Salamanca's car, Lord Rocksavage's car, certain test Chassis which have run long distances Paris Trials Cars, and the School Car. These are all standard Cars and are lubricated with Price's Oil, in accordance with our present standard practice. With regard to modification being experi- mented with to overcome the fault experienced on the Experimental cars mentioned, the Practice of increasing very considerably the clearance on the top band is not a complete cure but it certainly delays the appearance of the fault. Contd. | ||