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).
Experiments to eliminate engine knocking, including piston and bearing modifications.
| Identifier | WestWitteringFiles\C\August1919\ Scan61 | |
| Date | 29th August 1919 | |
| R.R. 235 A (100 T) (S F.{Mr Friese} 575, 16-4-19) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2354 Cont'd.{John DeLooze - Company Secretary} 3. EH4/LG29.8.19. ----------------- We are still investigating to see how the out-of-alignment in other directions besides tilting, affect knocks. We have tried numerous other things to try and overcome knocks. We took a piston which knocked and bedded the surface so that when it rocked over against the cylinder wall, it bedded over a certain area instead of on one point. The idea was to try and have a pad of oiled surface which would first come in contact with the cylinder wall. Although we tried this on each side both top and bottom, we could find no advantage. We also tried a spring as shewn herewith:- [Drawing of a piston with springs] with the idea that it might alter things. We could find no advantage in this with any reasonable strength of spring although we have noticed since in this weeks "Motor paper" that Crossleys' have patented this idea for overcoming knocks. WE have also tried tight and slack fitting connecting rod bearings with no result. We have also tried some pistons made of crankcase alloy which Mr. Hall thought would not expand as much as the present piston alloy. Contd. | ||