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).
With diagrams detailing modifications to the Phantom II Invar piston for improved flexibility and fit.
| Identifier | WestWitteringFiles\U\2January1930-September1930\ Scan016 | |
| Date | 23th January 1930 | |
| HS.{Lord Ernest Hives - Chair} FROM E.{Mr Elliott - Chief Engineer} ORIGINAL. PHANTOM 2. INVAR PISTON. We note from your reports that these pistons are likely to give as much trouble as cast iron in respect to precision of fit unless some flexibility is introduced. Compared with an all aluminium piston they should be able to operate with very little flexibility, and we suggest that a quick means of testing this would be to saw-cut the existing pads as shewn in sketch, arranging at the same time for suitable curvature, and fit, to bring the bedding right when hot. Our practice is to use flexibility on the non-pressure side only. The spring flaps would then require peaning out on the back like piston rings to introduce the necessary set. Alternatively the flaps could be drawn in with two or three countersunk screws in the split while being ground. There is no other way we can see at the moment of getting the bedding right, together with the spring on the flap. E.{Mr Elliott - Chief Engineer} x7040 x,506. | ||