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).
Proposed modifications to the Bensport piston design and production considerations.
| Identifier | ExFiles\Box 86\2\ scan0015 | |
| Date | 14th March 1933 | |
| X236 To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} Ws. By/SS.{S. Smith} re Bensport Pistons. -------------------- With regard to the Bensport piston which is .032" higher than the standard, we propose to utilise the existing dies and make the crown of the piston .032" thicker. This means an addition of .38 of an ounce in weight but as the standard pistons weigh 14 3/4 oz. and the sandcast pistons actually used on the first Bensport weighed 1 lb. the final Bensport pistons will not be as heavy as the original set tested. For the further assistance of production we think the piston rings can be the same distance from the centre of the gudgeon pin as on the standard piston. This, it is expected, will avoid mistakes in machining which might arise due to the close similarity of the two pistons which will be in production simultaneously. The slightly increased thickness of the crown we think may be beneficial for use in connection with the higher output of the Bensport, and after some experience with this engine there is a possibility that we might have to remove a little of the added height due to the tendency of the pistons at high speed to rise above the top surface of the cylinder block. E.{Mr Elliott - Chief Engineer} | ||