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 providing troubleshooting advice for a butterfly throttle that does not close completely.
| Identifier | ExFiles\Box 71\4\ scan0061 | |
| Date | 16th March 1925 | |
| +8940 Expl: Dept. Messrs. Rolls-Royce Ltd., Derby, Angleterre. 16th. Mar. 1925. Hotel De France, Chateauroux, Indre, France. Mr. Lidsey from hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} We understand that you are having trouble owing to the fact that the butterfly throttle does not close completely. We suggest that you find the pull which is being exerted by the throttle closing spring. This can be most easily accomplished by measuring the distance 'X' when the throttle is closed, removing the spring and taking the load at that extension by means of a spring balance. The pull we are recommending for use on 'V' series is 2.75 lbs. Should the pull you are obtaining be less than that, it can be easily increased by bending up the small tongue 'A', loosening the nut 'B' and rotating the spring supporting lever about 'B', clamping it up again by means of the nut 'B' when the spring is sufficiently extended. If the throttle still does not close, with the spring exerting this tension, we should be interested to know if the spindle is perfectly free when the spring is removed, as we estimate that this is just double the closing torque absolutely necessary. One other point is the mouse-trap spring which return the camshaft. This is to be found on the throttle governor casing. It should exert a force of over 1 lb. at the end of lever E.72643 when the throttle is fully closed. This should move the car clear of the arm marked 'Z' when the throttle is closed. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} | ||