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 Crossley Motors Ltd. regarding a special bearing material, clearances, and big-end bearing grooving.
| Identifier | ExFiles\Box 116\1\ scan0167 | |
| Date | 19th September 1938 | |
| 1020a (Experimental Dept.) Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} 19th September, 1938. Messrs. Crossley Motors Ltd., Gorton, Manchester. Your Ref: WOT/LD. Dear Sirs, In reply to your letter of Sept. 9th, the special bearing material referred to is known as A.C.9., and is being handled commercially by - Messrs. Wellworthy Piston Rings Ltd., Lymington, Hants: We are forwarding your communication, therefore, to the above firm together with a copy of this letter. Having had the opportunity of inspecting the drawings you have supplied, we would like to make the following observations:- (1) Clearances. The recommended clearance to run with this material is .00125 to .0015 per inch diameter; so that the actual machining dimensions and limits should be kept within that range, according to the dimensions of your crankshaft. (2) Grooving of big-end bearing. We note that your drawing of the top half of this bearing has a groove cut right through the shell, and we assume that this is for lubrication up the rod to the little end. | ||