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).
Design specifications for the Japan Cylinder Head and Valve Rockers, referencing drawing LeC. 2929.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan331 | |
| Date | 24th July 1931 | |
| ORIGINAL JAPAN CYLINDER HEAD AND VALVE ROCKERS. Bl. FROM E.{Mr Elliott - Chief Engineer} C. to Sl. WDR. HS.{Lord Ernest Hives - Chair} E1/M24.7.31. 15050. We send herewith LeC. 2929. shewing the above. The cyl. cetres of this engine have been expanded from 4.15 to 4.4 on the intermediate bearings, but on the central bearing they are only 4.5 as compared with 4.65". It is intended to locate the crankshaft at the central bearing so that all the remaining bearings including the double rear will be interchangeable. We have shewn the usual plugs for core cleaning on this drawing but as it is impossible to view the head from one end to the other on the ignition side due to the lower position of the sparking plugs we have omitted to supply holes at each end of the casting. We should be glad if the Works would go over this design to see if they want any more core plugs in the head, or if they want any of those shewn moved in position, so that the necessary alterations can be made. The valve rocker gear has been divided up into 2 units to overcome some of the expansion troubles, and each unit is supported by 3 mild steel brackets, one in between each pair of rockers. All rockers are interchangeable so that there will be only one stamping and one piece number to deal with in respect to this part. The clearance adjustment for the valve gear is on the rocker itself, and is of one of the three types of which drawings went sent to Derby for the preparation of models. The type of adjustment selected is the one which we think will be preferred when these models come to be examined. LeC. 2929. also shews particulars of the cyl. gasket and some of the particulars of the cyl. block. Drawings will be sent later dealing with the remainder of the last mentioned, together with the crankchamber, of which it forms part. E.{Mr Elliott - Chief Engineer} | ||