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).
Change in piston design to a three-ring arrangement for Eagle, Falcon, and Hawk engines.
| Identifier | ExFiles\Box 35\2\ scan 010 | |
| Date | 28th January 1916 | |
| To By from R.{Sir Henry Royce} c. to J.{Mr Johnson W.M.} c. to Na.{Mr Nadin} c. to Wor.{Arthur Wormald - General Works Manager}for Eh. c. to EF. c. toE. RE PISTONS. Mr Hives has decided that three rings would be preferable to the two-ring arrangement in the upper part of the piston, and that it is settled that the scraper ring must be on the extreme bottom edge of the piston. We fear that the present castings are not the best that can be devised for this alteration to the scrapere ring, and the cutting away of the bearing surface below the scraper ring. We therefore send herewith an improved design suitable for the "Eagle", "Falcon", and "HAWK" and the car engines, to bring them all in line and take full advantage of the knowledge gained by recent experiments. You will notice in these designs Mr.Elliott has brought the lower flange into a position approximately the centre of the bearing surface of the lower part, and that the piston pin is dealt with in rather a new way. At the same time as making these alterations, we are of the opinion that it would be as well to have no holes through the body of the piston so taht we can take advantage of the gas tightness of the scraper ring in addition to the three upper rings. We shall be glad if you will put these in hand at once, for experimental confirmation. They are urgent and important. R.{Sir Henry Royce} | ||