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).
Use of aluminium bronze for valve seats and methods for their installation.
| Identifier | WestWitteringFiles\P\July1926-September1926\ Scan123 | |
| Date | 27th September 1926 | |
| TO HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} re. VALVE SEATS. X8060 L3822 27. Sep 1926 We hear that the Americans are entirely in favour of aluminium bronze for valve seats, even though the appearances after preliminary runs are a little bit disappointing. They also say that this alloy can be materially improved by heat treatment after casting. You will see that we have expressed a view that the valve seats must be put in with a serrated driver, so as to better judge their tightness, that as soon as possible a little more thread shall be provided, and also an undercut or other locking arrangement will be provided. These precautions, together with the triple valve springs which give much less motion to the valve, and with the outer valve spring coiled in a direction that the motion due to this spring shall be in the right direction to screw in the valve seat, should be taken at the earliest possible moment. In addition HS.{Lord Ernest Hives - Chair} remarks that any screws in aluminium should be fitted with inserts as the stripping of threads in aluminium seems a regular fault. Personally I have not seen the aluminium correctly tapped for the steel screws. I think there should be taps of definitely smaller size, that will enable the screws and studs to be put in with a tight thread. There is much to be learned from the American practice. R.{Sir Henry Royce} | ||