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).
Cost analysis comparing three different methods for treating excessive cylinder bore wear.
| Identifier | ExFiles\Box 132\5\ scan0106 | |
| Date | 1st July 1939 | |
| -4- Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}5/MH.{M. Huckerby}1.7.39. Cost Analysis of Various Cylinder Treatments. With reference to the attached chart. The purpose of this is to compare approximate costs of three different possible methods of getting over excessive cylinder bore wear. We have arrived at this chart in the following way. We first obtained from Leyland Motors the machine operation list of their Phosphor Chrome liner. This was handed to our Operation Planning Dept. who prepared a similar operation list. The Estimating Dept. then filled in the times for each operation, and supplied the equivalent factory costs; these include overheads. For comparison with Leyland's figures, the times for the four rough machining operations are interesting, because they are twice the time taken by Leyland to do the same job. The figures for fine boring and honing are our own, based on the present cost for the standard Wraith block, because it is safe to assume that after pressing in the liner, the final operations will be as for a normal cylinder block. With reference to Leyland's figures, we have had to assume that labour and material fully cover the items they refer to, in their operation list. Finally, we think that the estimated cost for the four rough machining operations is excessive at 4/8d. each, because The British Piston Ring Co. of Coventry have recently machined the same castings for 3/6d. each, and we can assume they made a profit. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} | ||