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).
Overcoming piston knock, the production delays caused by a Moulders' strike, and the consideration of cast iron pistons.
| Identifier | ExFiles\Box 35\2\ scan 171 | |
| Date | 12th December 1919 | |
| R K.{Mr Kilner} 535 a (100 T) (S'y 846 6-8-19) O.{Mr Oldham} 2460 Contd. -2- Hs{Lord Ernest Hives - Chair}3/LG12.12.19. best thing we know of to overcome piston knocks, we think that the design of those pistons, as split pistons, should be the best we can do. The outstanding virtue of the split pistons is the fact that it is impossible to seize them up on the fitting portion. We are getting, on some of the cars, a slight knock when the engine is hot and just turning over slightly. This knock occurs with either the split type or solid trunk type piston. The characteristic of the knock is not like a piston knock; it is very elusive and difficult to trace! We are investigating the cause of it. We feel very anxious about the pistons positions because there is no doubt that we shall never satisfy the Sales Dept. until we supply them with an engine which under no con-dition can they find a knock. At present the Works are pro-ducing a very few pistons because of the Moulders Strikde, but as soon as the Strike is over, the Works will have a start on a very large batch of pistons. There are a great number of cars now simply waiting for pistons and the number increase daily. We think it is worth while reviewing the piston question once more with reference to what is the best thing to do when the Moulder go back to work. 4 We recommend that we reconsider the question of using cast iron pistons or at least we ought to have a design of cast iron pistons ready and being tested in case we cannot obtain absolute silence and reliability with the aluminium. Contd | ||