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).
Visit to John Marston Ltd. to investigate oil cooler failures and compare manufacturing methods.
| Identifier | ExFiles\Box 131\5\ scan0089 | |
| Date | 28th June 1938 | |
| 1114 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Std. c. HS.{Lord Ernest Hives - Chair} c. RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}/Std.1/MH.{M. Huckerby}28.6.38. VISIT TO MESSRS.JOHN MARSTON LTD. IN CONNECTION WITH REPLACEMENT OIL COOLERS. Although no 'F' type coolers have given trouble in service, we have failed two on an engine which we are using as a water pump test rig, which suffers from excessive vibration, and examination of the failures indicates a poor solder bond, due primarily to defects in the metallic contact between the case and the tubes. It will be remembered that we sectioned five of the first 'F' type coolers made and that the solder bond was thoroughly satisfactory on them - we have since taken two 'F' coolers at random and sectioned them with the same result. In view of the above failures, however, and in order to neglect no opportunity to increase the reliability of the replacement coolers, the writer and Mr.Smith, our Radiator Shop foreman, visited Messrs. Marstons on Friday last in order to discuss the methods of building the replacement coolers, and in particular the method which our radiator shop used for the first 30 coolers or so which were built at R.R. Ltd. Although we have previously tested an R.R. built cooler against the Marston coolers and obtained an inferior result (see HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}1/CB.10.1.38) nevertheless approx. 10 R.R. built coolers which were fitted to the first Ph.III cars have been removed from cars in the course of the changeovers being made, and none of these were found to be leaking - we have sectioned one of these and found the solder bond to be excellent. After discussion we were unable to arrive at any reason why the R.R. method (silver soldering case together and then dip soldering tubes into the case) should be better than the Marston method (dip soldering tubes to form block and then dip-soldering outer portions of casing onto the block, finally hand soldering the joints between individual portions of the casing) but agreed that apparently the R.R. method gave the best results, and Mr.Smith built a new cooler by the R.R. method while at their works - we have brought this back for test and sectioning. | ||