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 Morris Motors discussing manufacturing costs, gearboxes, pistons, and engine component tests.
| Identifier | ExFiles\Box 128\1\ scan0332 | |
| Date | 23th May 1938 | |
| MORRIS MOTORS LTD. ENGINES BRANCH COVENTRY. Date 23rd May, 1938. To W.A.Robotham, Esq., Messrs. Rolls-Royce Ltd., DERBY. -2- Please note that the 1/6d quoted is, of course, basic rate only, and does not include overtime charges, National Award, inspection of our own machining, or setting up charges. These are fixed weekly charges, and do not rise and fall with any change in man hours required for machining and assembling. To arrive at the figure required, the total labour charge must be assessed on the same basis, and is therefore the sum of all the 1/6d's spent on the items quoted, but excluding the fixed charges mentioned. Tool upkeep, pattern charges, and experimental charges are also excluded. The same calculation for the 25HP gearbox gives a figure of 21.8 man hours. I am sorry to be so long-winded about this, but I know how misleading these figures can be if they are not adequately explained. Regarding your question on the cost of pistons, we pay just over 5/- for a 2¾" piston, complete with rings and pin, bought in quantities of a thousand or so for special jobs. We get the same quotation from all well known piston manufacturers. I should say that a 3¼" bore piston complete should cost between 8/- and 10/-. We have not yet tried L section rings, because on our latest experimental engines we are having difficulty in persuading them to use sufficient oil. We are getting from 5,000 to 6,000 M.P.G. hard driving on well run in engines. I shall know more about this when we have had one or two cars on the road for twenty or thirty thousand miles, and if trouble starts we shall not forget your suggestion. I have seen Howlett re your bearings, and we are going to make some tests soon. Many thanks for your advice to try loose big end shells. We are getting 30% better results than with metal run straight into rods, and are standardizing this change on all future designs. I propose to send you a final "type test" of our latest 10HP engine as soon as it is available, and I shall be very interested to receive your comments. -contd- | ||