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).
Investigation into an elusive engine knock, potentially caused by piston or connecting rod side-play.
| Identifier | ExFiles\Box 77\3\ scan0122 | |
| Date | 20th February 1920 | |
| Contd. -2- Hs{Lord Ernest Hives - Chair}5/LG20.2.20 each cylinder and running with the extra oil on the whole time until the cylinders are flooded with oil. We get this same light knock with the solid aluminium pistons as well as the split ones. It is a very elusive kind of knock. The fact of removing the cylinders and replacing them without touching any of the parts, will make it disappear and it will need a long run before it shows up. If we fit any new pistons it will disappear for a long time. We feel we shall find that this knock may be due to side movement on the connecting rod. We suggest trying some rods on which there is no excess of side-play on the rods on the crank pin but that the float is allowed between the small end of the rod and the piston. Hs.{Lord Ernest Hives - Chair} | ||