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).
Engine design challenges for the Japan 3 engine, covering flywheel fixing, flexibility, and valve types.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan312 | |
| Date | 7th February 1931 | |
| E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair}) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} ) (At Le CanadelHenry Royce's French residence.) SECRET. R2/M7.2.31. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to RG.{Mr Rowledge} HY.{Tom Haldenby - Plant Engineer} RH.{R. Hollingworth} JAPAN 3. ENGINE. X5770. As regards the double bearing scheme and the difficulty of fixing the flywheel this was always one thing that made us shy of putting the gears at the back without a good reason. Now the increased engine revs. and the necessity for a fairly effective flywheel has forced us, we can only do our best to make a reliable job without excessive cost, but we must have no failures. One feels that type (1) is the best, and next to this our own patent type (2). Nothing else I have seen is worth a second thought. Now I think these ring nuts of great diameter cannot force the parts together but are useful after they have been permanently put together by other means, preferably hydraulic press that one can read the water pressure needed to push them home. The gear wheel and the hub to carry the flywheel can be looked upon as a permanent assembly and treated accordingly because if the gear wheel is to come off it can be looked upon as scrap, but not the crankshaft. My impression is that much of the flywheel flexibility may come from the flange fitting which was never designed for stiffness sideways. Would it not be good to fit more bolts - i.e. not taper or tightly fitting in the stems, trusting to the friction only as I believe is our modern practice so that the bolts are not costly. But test and find what is the effect of extra bolts (double the number) and also the advantage of wider faces i.e. more heel each way. I have not time to write more at the moment. Mr. Hives may be pointing out that side valves are less expensive than overheads, but I have got the impression that overheads suit us best, principally that I understand they are better for volumetric efficiency, both in the size of the valves and filling up - i.e. the charge is less heated before compression. We also get a better head joint and less weighty engine. In other words we should want a larger and heavier engine for the same performance. R.{Sir Henry Royce} | ||