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).
Procedures for checking petrol levels and flow in a carburetter float chamber.
| Identifier | ExFiles\Box 66a\1\ scan0035 | |
| Date | 25th September 1924 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -5- Expl. No. REF:Hs{Lord Ernest Hives - Chair}/ACL/LG28125 petrol in the float chamber. When the petrol is first turned on, the glass tube should be lowered for a second so that petrol runs from the top, this is merely to ensure that there is no air lock in the system. The petrol level measured from the top face of the float chamber should be between 1.2" and 1.4". It should be allowed to stand with the petrol turned on for a few minutes to see if the level rises. If the petrol rises, this usually indicates that it is leaking passed the conical needle valve. On no account should an attempt be made to alter the level by placing washers under the valve seating, by bending the float weights or by altering the position of the collar on the needle valve. The float mechanism is arranged to operate in the best position and any of the above operations would tend to impair the correct functioning of these parts. (see print attached) Petrol passages. All petrol passages must be quite free and contain no burrs. The petrol flow through the feed passages ought to be checked. A 15" head should be used. It could be done in the following way :- Fix up a petrol tank so that the surface of the petrol is 15" above the top face of the float chamber. Connect the tank with the carburetter feed union and remove the plug from the bottom of the high speed jet tube. Petrol should flow through this plug hole at a rate of not less than 75 pts/hr. (see print attached) contd :- | ||