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).
Secret memorandum on carburetter design considerations for the air valve, piston, and throat.
| Identifier | ExFiles\Box 66a\1\ scan0007 | |
| Date | 18th July 1924 | |
| X. 8080. To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to CJ. BJ. RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} PN.{Mr Northey} S E C R E T. R1/M18.7.24. E.A.C.11. CARBURETTER. X. 8080. LIGHTER AIR VALVE. We have now sent you two designs for the lighter air valve; one in brass, the other in aluminium. We think it will be as well to make both of these with the minimum of tools necessary, and after testing, make the proper tools for the preferred one. SPRING UNDER PISTON. While these are being produced you can use the spring under the piston as suggested, so as to balance its weight to any extent desirable. We think that the lighter piston will probably be the better idea to adopt finally. Either piston should fit standard chambers, and the standard chambers should fit the present standard carb. The piston chamber however may require some slight alteration for the spring underneath the piston. LOW SPEED THROAT. I am inclined to think that there should be no difficulty in using either a .65 throat, or a .6 throat for the low speed. A smaller throat giving the advantage at the air valve will be always floating, (providing it does not exceed 6 ozs.) and it is possible that you will not get this to float easily enough without adopting the smaller throat. R.{Sir Henry Royce} | ||