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).
Future of compression ignition engines, specifically comparing 2-cycle and 4-cycle designs.
| Identifier | WestWitteringFiles\U\2January1930-September1930\ Scan266 | |
| Date | 31th August 1930 | |
| RG.{Mr Rowledge} ) FROM R.{Sir Henry Royce} HS.{Lord Ernest Hives - Chair} ) C. to SC. WOR.{Arthur Wormald - General Works Manager} ORIGINAL COMPRESSION IGNITION ENGINE. FUTURE. We have done fairly well with our unit but it does not seem possible that the best engine for weight/power ratio will be made like this, or exactly like any of the 4 cycle engines at present being made - i.e. Farnborough's attempt with RR. Condor parts, or Ricardo's attempt with RR. F.{Mr Friese} engine parts. Mr. Ricardo says we must have swirl or other turbulence for good fuel economy, and we think this is best obtained with piston covered inlet parts, or sleeve engine. Such schemes provide easy means of adopting a 2 cycle engine, which, although I definitely dislike for petrol or paraffin engines where the fuel goes in with the air, I suggested that it is quite passable for a moderate speed compression ignition engine, and providing Mr. Ricardo agrees that this is the most hopeful scheme for getting a good engine we ought to make a cylinder unit of this type for our single cylinder unit. This was my state of mind before our visit (RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} & R.{Sir Henry Royce}) to Mr. Ricardo's Works last week. Mr. Ricardo strongly recommended this course. It will be noted that the 2 cycle has not got so far in development as the 4 cycle, and if we were in a great hurry to produce an engine that would be certain of success I should vote for sticking to the 4 cycle system. The 2 cycle will I am sure (if it can be made thoroughly reliable) make an engine which is so much smoother in running with a practical number of cylinders, or an equally smooth engine with less cylinders, as well as probably a lighter engine per BHP., especially if its more moderate speed avoids the necessity of a propeller reduction gear. Mr. Ricardo's efforts have shewn one or two serious difficulties belonging to this type, some of which we foresaw, but he thinks they are not insurmountable, but I fear they are definitely disadvantages of the 2 cycle scheme. NON-SLEEVE TWO CYCLE. For a simple engine I have suggested a combination for a 2 cycle engine which is new, and there is a chance of its being valuable. It seems so extremely simple that one thinks it must have been tried before, but with more recent developments, and (1) | ||