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).
Observations made at Leylands, concerning their use of alloys, die-cast aluminium gearboxes, and experiments with chromium-plated cylinder bores.
| Identifier | ExFiles\Box 140\3\ scan0056 | |
| Date | 25th August 1936 | |
| -4- It seems to us that one way where we can definitely keep ahead of the Americans on power weight ratio is to use alloys which they cannot afford to incorporate in their chassis. We attach a list showing the possibility of magnesium on the Ph.III. Other points of interest noticed at Leylands were - (1) They have had complete success with RR.53 big end bearings. The only reason they have discontinued using them is because they have been unable to get supplies of RR.53. This seems rather an unsatisfactory state of affairs from our point of view. (2) The gearboxes they are producing in aluminium are being die-cast. They state that this saves them in cost and weight and gives them a better job. Where necessary they use sand cores. It is the first time we have seen gearboxes die-cast in aluminium, and they certainly seem to be an excellent job and one which we could with advantage investigate further. (3) Leylands have of course exceptional opportunities for getting information on cylinder bore wear. They state that on their petrol buses used for services where starts and stops are being made, the cylinder wear is the greatest. This reaches as much as .001" per thousand miles. To overcome the trouble they have been trying chromium plated bores and the wear has gone down to less than .001" in 10,000 miles. They are carrying on with the experiments, which seem promising. Their difficulty is, however, that their buses have to go all over the world and in many cases their customers have not the facilities for re-boring should this be necessary, if chromium plate has to be removed in the process. This information was of considerable interest to us as we are just starting a series of experiments on chromium plated cylinder bores. Leylands point out that with compression ignition engines their cylinder bore wear is a great deal less than with petrol. This rather explodes the theory that condensed fuel has nothing to do with cylinder wear. Mr. Pilkington hopes to be able to visit us in September, when they will have further information on some of the points we raised with them. | ||