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).
Three materials for pistons, their associated designs, and an issue with piston pin fixing.
| Identifier | WestWitteringFiles\P\July1926-September1926\ Scan104 | |
| Date | 9th September 1926 | |
| TO HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} (Handwritten text below, struck through: DY.{F R Danby} RG.{Mr Rowledge}) (Handwritten text below, struck through: C. to BJ. WOB.) (Stamped in blue ink: ORIGINAL) (Handwritten: 4-0 10/9/26) (Handwritten: <strike>X4004</strike> X2603 X3996) re. PISTONS - GENERAL One understands there are 3 materials for pistons - (1) 7% copper with 93% aluminium - (castings for general use.) (2) Y. metal forging, machined for greatest strength - i.e. aero engine work (Condor.) (3) Magnesium copper alloy drop forging to pattern, (double bolt pedestal) for the very lightest type. This is to be tried on Phantom. Each of these materials permits or demands a special design of piston, and we have - (a) A type with complete trunk with cross webs for (1) LeC.2291.* (b) The Peter Hooker type of trunk piston for (2) - LeC. 2268. (c) Pedestal 2 bolt type for (3) - modified and lightened to LeC. 2292.* Regarding piston pin fixing for (1) and (2) designs, it is reported that the plugs by mysterious expansion creep into the pins, shear the small collar, and get below the steel end. Is this so? We need confirmation as it is astonishing. But if it can be so easily cured by making the plugs a running fit, and should make this scheme right, and as it is the simplest, it should be tested out. Failing this we have requisitioned the spring ring type to our special scheme LeC. 2285. R.{Sir Henry Royce} *LeCs. 2291. and 2292. are being drawn. | ||