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 to Zenith Carburetter Co. Ltd. detailing required modifications for choke valve clearance issues on 30 HP D.C.42 carburetters.
| Identifier | ExFiles\Box 122\2\ scan0230 | |
| Date | 22th September 1937 | |
| 1033 Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}3/MH.{M. Huckerby} 22nd. September 1937. Messrs. The Zenith Carburetter Co. Ltd., Honeypot Lane, Stanmore, Middlesex. For the attention of Mr. A.E. Palmer. Dear Sirs, 30 HP. D.C.42. With reference to the complaint of choke valves not closing on the above carburetters. We find that more clearance is necessary in the bearings of the choke valve spindle. The diameter of the bearings is at present .250" to .251". (1) This should be reamed .253" diameter for freedom in operation. (2) The spindle also requires a slight modification, in that the plating should not overlap into the bearing section either end. (3) A further suggestion is that the choke body be chamfered, just before the sealing of the butterfly on each side; to counteract any side thrust by the torsion spring. The above was communicated to your Mr. Fisher who will discuss details of item No.3 with you. Will you please carry out modifications Nos. 1 and 2 immediately. | ||