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).
Summary of observations on cam ground, aluminium, and trans-slot pistons.
| Identifier | ExFiles\Box 170\2\ img215 | |
| Date | 9th November 1934 guessed | |
| 3 All pistons are cam ground and are a very pretty job. We dream of the day when we can produce a circular ground piston which will bed itself. Making an accurate job of the cams is very difficult & involves hand stoning. Ellio has a special indicator rig for gauging cams accurate to 1/100 of a thousand. "En somme :- Aluminium pistons have been a success. Trans. slot pistons about 1 1/2 thou slack cold and 7 thou. slack on the sides promise to be even better. Low oil consumption at low speeds is a trouble. Cold starting has not been a trouble. Cold knocks & hot idle knocks have not been a trouble. Power is greater with the trans. slot piston. En bloc cylinders introduce new troubles not yet thoroughly understood. | ||