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).
Modifications to piston design, including increasing skirt length and experimenting with spring pressure.
| Identifier | ExFiles\Box 35\2\ scan 134 | |
| Date | 24th September 1919 | |
| To EH. from R, Copy to CJ. " " EN. " " WOR.{Arthur Wormald - General Works Manager} X.2748 RE PISTONS. R10/G24.9.19. X.3651. X.2748. I am pleased to hear that the longer piston promises to be better. Get the works to run from hand to mouth, as an increased length of skirt can soon be fitted, and is almost a certain improvement that would be without risk or likely to cause any trouble. I think, however, you should push on with the spring pressure, keeping the piston to the working side of the cylinder. Even if this is thought impracticable it might give us some idea of the pressure required to keep it free and it may give us a piston which renders the engine as a whole quieter than we have previously experienced. Supposing the pad of metal had sufficient area that it did not press on the cylinder walls greater than the pressure of the piston rings, it might be considered practical to fit it with springs, specially if we could rely upon the lubrication being fed in at this point from the connecting rod. I suggest 1 1/4" added to bottom making a 6" long piston as a practical amount that might be adopted at once if found to be any promise of improvement because it can be cut off in a minute if found of less than no value. R.{Sir Henry Royce} | ||