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).
Design and advantages of three different types of pistons for experimental testing.
| Identifier | ExFiles\Box 65a\1\ scan0041 | |
| Date | 18th May 1926 | |
| Contd. -2- crown pistons which push the XXXXX rings higher up and enable us to improve the general design and possibly that of the piston pin. The first one, Lec.2245, is like the present, but will be found more flexible, the pin in a better position, and the body a little longer. We think this should have a distinct advantage over the present piston but will be found to be still subject to piston pin knocks owing to the difference in the expansion unless put together hot and carefully sized. The other two pistons include Lec.2237 the pedestal type which you have already tested and favoured, but which has now been improved in dimensions, and Lec.2243, a single bolt type with aluminium seating for the pin, which might be called half pedestal type. These two pistons should have no piston pin knocks, and less cylinder knocks. Outside our firm they are novel in design, one of which you have already tested and reported upon, but which had certain weaknesses which we hope you have reduced. These three pistons ought all to be made experimenrally and if any one of them shew distinct advantages over the present standard it should be fitted to EAC.8. R.{Sir Henry Royce} | ||