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).
Report comparing the current cylinder design with an alternative steel cylinder construction using hydrogen brazing.
| Identifier | ExFiles\Box 173\1\ img185 | |
| Date | 20th January 1934 | |
| COPY OF REPORT RECEIVED FROM HEC. IN U.S.A. DATED 20.1.34. To Mr. Iron RM{William Robotham - Chief Engineer}/HEC. HE/HEC. R/RM.{William Robotham - Chief Engineer}J.3.34. c. to W.A. c. to RG.{Mr Rowledge} c. to L. c. to By.{R.W. Bailey - Chief Engineer} c. to Lic c. to Lp.{Mr Lappin} c. to F.{Mr Friese} CURTIS CONDOR. Cylinder Construction. Present cylinder design is a source of trouble, chiefly on account of manufacturing difficulties. Extreme accuracy in machining of cylinder liners and head is necessary since roof of liner must fit perfectly to cylinder head. Conductivity must be poor. The machining of threads must be perfectly square so that in final assembly liners are perpendicular. Owing to the difficulties which are encountered, alternative cylinder construction has been designed, which consists of separate all steel cylinders, having six holding down bolts at base flange, and jacket made in tubular form braised in position. Whereas this arrangement has not been subjected to type test, development experience is most satisfactory. The valve port project on top of liner provides spigots for location of cylinder head, which is one piece aluminium casting. The water jacket is made tubular steel form having three corrugations and cylinder diameters are stepped so that jacket can be threaded into position. This construction has been made possible due to progress of hydrogen brazing which is now being used extensively. Parts to be braised are copper plated, both internally and externally. After jackets are fitted and unit is prepared for brazing, it is placed in a hydrogen furnace and heated to 1100C and brazing takes place, no fluxing being necessary. So far this design has proved to be thoroughly reliable. Local stresses in cylinder jacket does not occur since brazing temperature is uniform. Production costs are very much lower as compared with aluminium design, and decidedly lower than original arrangement of built up steel jackets, which required so much hand work. The butt-ended cylinder liners prevent intrusion of loose type valve inserts in alternative materials. | ||