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).
Three schemes for the revision of the 25HP 'Japan' engine.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan057 | |
| Date | 13th November 1930 | |
| BY.{R.W. Bailey - Chief Engineer} FROM E.{Mr Elliott - Chief Engineer} C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to HS.{Lord Ernest Hives - Chair} HY{Tom Haldenby - Plant Engineer} REVISION OF 25HP. ENGINE 'JAPAN'. RECEIVED 13 NOV 1930 ORIGINAL X5770 X5050 X5230. We send you herewith three schemes as follows dealing with the above:- LeC. 2833. CYLINDER HEAD. This is on the lines of the present 'Japan' with 6 inlet ports on the steering side of chassis, but is of cast iron, and arranged to take two ignition plugs per/cyl. if and when required. The core boxes should be made so that the boss for the extra sparking plug can be put in at will as it is not intended to standardise twin plugs. When the sparking plug boss is left out then the cylinder stud bosses have to be ribbed to the cylinder head instead of to the plug boss as shewn in the drawing, and vice versa. This cylinder head will not fit any existing engine, but a suitable cylinder and crankcase is shewn on LeC. 2838. attached. LeC. 2835. EXHAUST MANIFOLD. This manifold is on the lines of P. 2. and is arranged to admit of the use of the extra set of sparking plugs should these latter be required. LeC. 2838. GENERAL DRAWING SHEWING SECTION THROUGH CYL. BLOCK & CRANKCAS AND GIVING PARTICULARS OF CON. ROD, PISTON, VALVE GEAR ETC. The con. rod has been increased in length to render the engine smoother in operation on the over-run, and at the same time it has been made with a parallel stem machined only within the panels of the 'I' section to facilitate production. The valve tappet gear is on the lines of P. 2. but the lubri-cation has been improved by completely enclosing the camshaft within a tube formed integrally with the crankcase, which tube will be flooded with oil. Tappet guides are located by a scheme which should be satis-factory for interchangeable production, and these guides in turn position the camshaft bearings endways. Further schemes will follow giving remaining particulars of the crankcase, wheelcase, and gears, etc. E.{Mr Elliott - Chief Engineer} | ||