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).
Comparison of 'Aerolite' and 'R.R.' piston manufacturing processes, including gudgeon pin fit, machining, ageing, and pressure testing.
| Identifier | ExFiles\Box 148\1\ scan0076 | |
| Date | 22th March 1939 guessed | |
| -2- Gudgeon Pin fit. Aerolite - Pin has clearance of .0002 to .0003. R.R. - Interference fit. Pin inserted initially by immersion of the piston in boiling water. NOTE. The Aerolite method of checking the actual clearance is very accurate and reliable. Location for machining. This takes the form of two small holes, on the underside of the gudgeon pin bosses. Ageing. Aerolite. - "Solution" treatment 2 hours quench in water. Precipitate treatment (2 hours at 180°C). Cool in air. R.R. Precipitate treatment (70 hrs. at 160°C). Pressure Testing. Aerolite. - None. R.R. - Oil pressure (Internal 650 lbs/sq.in.) NOTE. None of the Aerolite pistons we have used have been so tested, and they are more highly stressed than the R.R piston. Also the R.R. testing machine has never caused a die-cast piston to be rejected. CONCLUSION. First sample pistons to be produced by the Light Production Co. to our drawing EW.2121 (raised crown, splitskirt) will be made in accordance with their standard process, regarding the five major points mentioned. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} | ||