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).
Suggested letter to Mr. Pye regarding compression ignition engine development and research.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan334 | |
| Date | 14th February 1931 | |
| [Stamp: DERBY 21 FEB 1931 WILK!X] RG.{Mr Rowledge} HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} ) (At Le CanadelHenry Royce's French residence) [Stamped: ORIGINAL] R1/M14.2.31. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} COMPRESSION IGNITION. SUGGESTED LETTER FROM R.{Sir Henry Royce} TO MR. PYE. x4433 Owing to some mysterious troubles with our other work which have now become clear, and are launched on their way for a cure, our present staff and ourselves have not been able to give much thought to the above. We have now arranged for a special designer to be exclusively on this work under the direct supervision of RG.{Mr Rowledge}, with the help of E.{Mr Elliott - Chief Engineer} our chief designer, and HS.{Lord Ernest Hives - Chair} our experimental engineer. We did not intend to do much pure research work to find out what was needed for the designs of a complete practical engine, but to be guided by the work of the purely research people such as Mr. Ricardo, and those at Farnborough. We expected to have a clear programme of the requirements which we were to embody in a mechanically good design in the same way as we have done with the other aero work, that is, we should design our parts in accordance with these requirements and prove the parts in our single cyl. unit, and combine these parts into a complete engine. Our first attempt was to follow Farnborough's work on "Condor" and we made a cyl. which represented the more modern design of "Condor" hemispherical form which is still thought to be a good form for this type of work - i.e. for strength with uniform shape (space) all round a central nozzle. This model cyl. proved strong and convenient but did not give sufficiently good MEP. and consumption, and it was decided to alter the length of stroke from 6.5" to 8" which gave us the maximum stroke/bore ratio that would build up into an engine sufficiently light for its HP. For this reason we had commenced with the shorter stroke. Now with the exception of con. rod trouble our unit has run well and smoothly and my impression is that the results are nearly as good as we can expect with the volumetric efficiency and the poor mechanical efficiency of a substantial single unit running at very high speeds with a very heavy flywheel. We were hoping that Farnborough results would have told us what to do with this form of cyl. and engine speed, but the subject is so difficult at these high speeds (8" stroke, 2000 RPM.) that we have all come up against the same difficulty of getting good MEP. and consumption. As regards maximum cyl. pressure I am not sure that I have correct information in mind (for reasons already given) but my ideas are that we are all working with about the same compression ratio; owing to our long stroke we are not filling up very well (lower volumetric efficiency than Condor) yet we are getting higher maximum pressures. If all this is so then fuel injection is later in the Farnborough Condor than we are using. I mention this because it struck me as the reason why Farnborough found so much difficulty in getting the same HP. from each cylinder - i.e. (1) | ||