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).
Piston specifications and turbulence tests for the Bensport Engine.
| Identifier | ExFiles\Box 86\2\ scan0002 | |
| Date | 27th February 1933 | |
| X236. To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} re Bensport Engine. When the 3.25 bore J.l. engine was originally instructed to scheme 1585 the piston called for was E.56610 which comes flush with the top of the cylinder block. The standard 20/25 piston,however, in the course of time has grown to almost the same height as E.56610 with the progressive increase in compression ratio, and it is the standard piston E.57122 that has been used on the first Bensport car with the result that the piston top is .030" below the top of the cylinder block instead of being flush as intended. It, therefore, appears that E.57122 is the piston we shall have to instruct for the first Bensports. In the meantime we should be glad if the Experimental department would make tests with E.56610 to see what improvement, if any, is obtained due to increased turbulence. It will be remembered that our original experiments with turbulent heads showed that with a distance of .1 between the piston crown and the cylinder head the value of the turbulence was nil. E.{Mr Elliott - Chief Engineer} | ||