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).
The Daimler-Benz 750 BHP, 12-cylinder compression-ignition precombustion chamber aero engine.
| Identifier | ExFiles\Box 179b\3\ img167 | |
| Date | 7th February 1933 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/JS.{Mr Johnson's Secretary} c. Sg.{Arthur F. Sidgreaves - MD} Mor. c. Rg.{Mr Rowledge} K.{Mr Kilner} c. Hy.{Tom Haldenby - Plant Engineer} Pl. Hs{Lord Ernest Hives - Chair}/JS.{Mr Johnson's Secretary}G/KT.7.2.33. X4433 DAIMLER-BENZ 750 BHP. 12 CYLINDER COMPRESSION-IGNITION PRECOMBUSTION CHAMBER AERO ENGINE. It is reported in the issue of Automotive Industries dated Jan 21st 1933, that the Daimler-Benz Company of Germany, manufacturers of the well known Mercedes-Benz automobiles, will shortly announce a new 750 BHP. Diesel aircraft engine which, according to the figures and curves published in the report, has given in exceptionally good performance on the test bed. The introduction of this engine is of great interest for several reasons; it is, we believe, the first complete 12 cylinder C.I. aero engine utilising the precombustion chamber principle; it shows that in the opinion of a firm of engine builders of repute and great experience in compression ignition work that the precombustion chamber engine is suitable for aero work and has advantages over the direct injection engine, and the performance of the engine demonstrates that a combustion head, notorious for its high fuel consumption, when built in small cylinders working over a wide speed range, may give very good economy in larger cylinders working over a narrower speed range. The engine, which is illustrated by photographs reproduced in Figs. 1 & 2, has its cylinders in V arrangement. The bore is 6.5" and the stroke is 8.3" and each cylinder has two inlet and two exhaust valves which are actuated by two overhead camshafts, one for each row of cylinders. The fuel is injected into a precombustion chamber located between the four valves in the cylinder head. The principle of the Benz precombustion chamber may be seen from Fig.3, which shows, more or less diagrammatically, the general arrangement and form of the chamber. At the top of the chamber is fitted the fuel injector and at the bottom the "Flame plate". One form of this is shewn in Fig.3, and is a small round fitting having several small holes drilled as illustrated. This "flame plate" closes the precombustion chamber with the exception of the holes mentioned for the passage of the gases. | ||