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).
The trial of Bentley pistons submitted by Specialloid Limited, detailing issues found during testing.
| Identifier | ExFiles\Box 148\4\ scan0318 | |
| Date | 13th February 1935 | |
| X100 1 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}14/KW. 13th February, 1935. Messrs. Specialloid Limited, Friern Park, North Finchley, London, N.12. Dear Sirs, We have now run the set of pistons which you submitted to us for trial on the Bentley. As we rather anticipated, these pistons knocked when cold. We do not know whether you realise that a considerable proportion of the piston skirt projects through the bottom of the cylinder at bottom dead centre, and in view of the fact that your skirt tapers .0035, this probably has some bearing on the matter. These pistons are as good for power but no better than some of the other pot type pistons which we have been testing. At the end of the power curve before we had time to do any endurance running one of the pistons seized. We are returning these pistons to you under separate cover, for your examination. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||