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).
Letter discussing a change in material for carburetter air valves from aluminum to duralumin.
| Identifier | ExFiles\Box 122\4\ scan0011 | |
| Date | 26th May 1927 | |
| OyS-E-52627 X3675 May 26th, 1927. Mr. R.{Sir Henry Royce} W. H.{Arthur M. Hanbury - Head Complaints} Bailey, Rolls-Royce Ltd., Derby, England. (Copy for attention of Mr. Hives " " " Mr. Haldenby) Dear Mr. Bailey: Carburetter - Section 5080 Air Valve We have found it better (and we believe less expensive) to make the air valves from "duralumin" bar instead of an aluminum pressed blank. This gives an increase in hardness from about 30 to 90 Brinell. The soft aluminum we find gives a lot of trouble in service from picking up due to small specks of dirt, causing the valve to stick. It is also excessively difficult to machine. We originally used duralumin pressings of about 70 Brinell, but these are very expensive, and we think have no advantage over bar material Yours very truly, Maurice Olley MO/E | ||