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).
Technical memo detailing the design of the valve rocker gear and cylinder head for the 'Japan 3' engine.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan320 | |
| Date | 9th February 1931 | |
| SECRET. ORIGINAL JAPAN 3. VALVE ROCKER GEAR & DETAILS OF CYLINDER HEAD - Lec. 28 The above drawing completes and brings up-to-date the information with respect to the valve rocker gear and cyl. head. Attention is drawn to the following points: (1) VALVE ROCKER SHAFT & PEDESTALS. The shaft has been shewn in one piece as used on 'China' instead of two as used on Japan, since we are using a cast iron head and such provision for differences in expansion is rendered unnecessary. This also avoids complication in respect to the oil feed and multiplicity of pedestals. The pedestals have all been made interchangeable except that No. 1. has an oil groove in the base but up to the grooving operation is no different. It is expected that the rocker shaft will be purchased as a thick tube and hence the central hole will give no trouble. The spacing of the pedestals relative to the rockers is controlled by mild steel distance washers of the requisite thickness without which it would be necessary to have 4 or 5 varieties of pedestal. (2) LUBRICATION OF ROCKER SHAFT. On the present 25HP. engine where the rocker shaft is lubricated with oil at overflow pressure an extra feed has been taken to the rear end as shewn in the sketch. We think this will not be necessary on Japan 3. and that the distribution of oil along the rocker shaft will be satisfactory with low pressure oil. (3) PLUGGING OF CYL. HEAD. Derby would like us to use where possible expanded discs in place of screwed plugs. We propose to make the casting so that it is suitable for either method of plugging as shewn by the sketches. (1) | ||