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 from Zenith Carburetter Co. detailing proposed modifications for sample carburettors.
| Identifier | ExFiles\Box 122\3\ scan0252 | |
| Date | 7th March 1941 | |
| THE ZENITH CARBURETTER CO. Limited. Sheet No....-3-.... Messrs. Rolls-Royce Ltd., 7th March, 1941. this letter, and to have your comments upon it at your convenience. As regards the sample carburetters which we are about to prepare, you will appreciate that in order to obtain these, we shall have to use existing castings, and it will be necessary, in order to comply with certain parts of the above specification, that we shall modify those castings in the most convenient manner. The parts involved under this remark are :- a.{Mr Adams} The recess in the casting which we propose to use will have to be partially filled up in some way and machined out to allow the passage of the link between the choke valve and the fast idle piston. [Handwritten note: 1938 Cadillac 18-22 cc] b. The pump cylinder will have to be reduced somewhat in diameter. [Handwritten note: 1940 Buick 11-15 cc fast 15-19 cc slow middle pos'n] Furthermore, as regards the suction-operated advance, we propose simply to drill a hole in the throttle body adjacent to the edge of the throttle plate and to insert a small diameter tube so that connection can be made by means of rubber or similar substance with the ignition advance unit. We are returning to you with this letter a copy of your Drawing PL.196, on which Drawing we have marked certain dimensions it will be necessary we should have, before we can provide the levers and so forth which will meet your requirements. We shall be glad if you will kindly fill in the dimensions called for and return the Drawing to us with your comments. It is understood that we shall make up two sample carburetters, each provided with 36 m/m throttle bodies, and that in addition we shall provide two 30 m/m throttle bodies, which can replace the throttle body of the larger dimension. [Handwritten note: Idle jets same as on 36 m/m body] On your Drawing PL.196 we notice that you show the throttle lever and the throttle stop on opposite ends of the throttle spindle. Might we suggest that the throttle stop shall be placed on the throttle body on the same side as the throttle lever as being a better practice, since in this way the torque is taken out of the throttle spindle when the throttle plate is in the idling position. P.T.O. | ||