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 Leyland Motors to High Duty Alloys regarding clearances for R.R.56 connecting rods.
| Identifier | ExFiles\Box 85\3\ scan0064 | |
| Date | 15th September 1933 | |
| COPY FROM:- LEYLAND MOTORS LTD. Leyland, Lancs. To High Duty Alloys Ltd., Slough, Bucks. Sept.15th 1933. Ref. CGH{W Clough}/IS. METALLURGIST. Dear Sirs, R.R.56 Connecting Rods. The following particulars refer to the information for which Mr.Devereux asked in connection with clearances for the above parts. The clearance allowed for Connecting rods varies from .0010" to .0025" and is arrived at as follows:- Diameter of crankshaft journal - 3.0" - .0017" Connecting rod big end - 3.0" + .000" + .0008" These clearances are the same as used for white metal big ends. In the case of experimental big end shells made from R.R.56 alloy, it was found necessary to allow larger clearances, the actual value being .0030" to .0040". This was evidently due to the fact that the steel connected rod resisted the free expansion of the shell which consequently closes in on the shaft and seizes if a larger clearance is not allowed. We trust that this is the information you require. Yours faithfully, pp.LEYLAND MOTORS LTD. (Signed)V.W.Pilkington. Manager - Engineering Dept. | ||