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).
Throttle sticking issues and potential solutions for the Phantom II Semi Expanding Carburetter.
| Identifier | ExFiles\Box 13\4\ 04-page125 | |
| Date | 15th March 1933 | |
| X7080 E.{Mr Elliott - Chief Engineer}) from Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation} BY.{R.W. Bailey - Chief Engineer}) c. to Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation}9/KT.15.3.33. PHANTOM II SEMI EXPANDING CARBURETTER. Trouble has been experienced on production cars with throttle sticking. This was brought about by the effect of suction on the engine side of the throttle causing friction between the throttle spindle and bushes. The necessary effort to move the throttle was found to be in excess of the load exerted by the throttle return spring, thus the failure of the throttle to respond to the hand control. The present scheme embodies the use of a return spring pulling in the same direction as the suction at the back of the throttle, thus adding to the friction on the spindle bearings. By reversing the action of the spring to pull in the opposite direction, the loading necessary to close the throttle will also serve to reduce friction load from engine suction. The actual reduction of friction will be doubled, due to the removal of spring load; pulling in the same direction as engine suction. The use of Duralumin bushes on these carburetters for throttle spindle bearings was not found successful, they being very prevalent to picking up and seizure. In order to release cars at present held up on test we recommend that BZ/PC material bushes should be fitted. Hs{Lord Ernest Hives - Chair}/C. T. Salt. | ||