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).
Confirming a phone message about the development and considerations of a compression ignition unit, specifically a 2-stroke, sleeve-type engine.
| Identifier | ExFiles\Box 178\3\ img286 | |
| Date | 21th July 1932 | |
| RG.{Mr Rowledge} EX. FYE. } FROM R.{Sir Henry Royce} CONFIRMATION OF 'PHONE MESSAGE TO RG.{Mr Rowledge} 21.7.32. to WGH. SS.{S. Smith} HS.{Lord Ernest Hives - Chair} re. COMPRESSION IGNITION UNIT. At WW. we have been delayed somewhat with other engine work but are just about to complete the unit which we have had in hand for some time, (the chief features of which are the 2 stroke, sleeve type), not so much with the object of proving the suitability of the sleeve as of finding the best form of combustion chamber and the necessary port area for a high speed engine of the 2 stroke type. It will be realised how extremely convenient the sleeve valve engine is for varying the shape and scheme of combustion chamber, and obtaining ample port area, swirl or otherwise, and it should supply a rich field for experimental research. We have lately come to the conclusion that any piston used in a sleeve engine, or even in a direct watercooled engine, as an exhaust valve or port, must have oil or other fluid cooling to enable it to stand up to the high duty demanded in aerial work. I think the result that it is possible to obtain would well justify such features. We are assuming that this unit will enable the speed to be tested between 1500/2000 RPM., supercharged, and should give a high rate of HP. per cyl. capacity, even though the BMEP. may not be over 100 lbs. per sq. in. We have assumed that after finding from our present experiments, and the unit being designed at Derby, the best form of combustion chamber, nozzles, etc, we shall be able to reconsider what type of engine will provide the necessary convenience, that is, we may still wish to go back to a double piston, or retain this proposed sleeve type, or the poppet valve exhaust type, but at present the Company has no special experience of its own that indicates which type of engine may prove the best. Dr. Underwood is working continuously on this part of the programme. We have noticed that it is possible that with a compression ignition engine the sleeve may behave far better than it did in connection with the petrol engine, the reason being that the combustion may be even around the centre of the cyl., and may be free from detonations, and less hot at the beginning of the exhaust period. Naturally there will be corresponding disadvantages with the indirect watercooling of the sleeve, and with the frequency of the exhaust in a 2 stroke scheme. R.{Sir Henry Royce} | ||