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).
Notes on engine development including piston lubrication, cooling systems, and direct injection.
| Identifier | ExFiles\Box 179b\3\ img143 | |
| Date | 6th October 1935 guessed | |
| -5- They are building another engine which I saw and looks similar to a Buzzard cylinder. The valves are not inclined on this one. It has variable comp. ratio and several holes for nozzles and plugs. It is made to run up to 3000 r.p.m. They have constructed a spray nozzle unit no bigger than a 14 m.m. spark plug. The new engine is to have sodium cooled valves by the Rich Co. C.I. Piston Lubrication. Some of the C.I. pistons I saw had most of the centre bearing face cut away, and the top and bottom bearing lands were drilled with holes in communication with the main pressure feed passing up the drilled con. rod. They say that a second or so after starting up all the usual C.I. piston slap disappears. This might be interesting on cars? Packard Diesel. One of Packards troubles was extremely rough operation and smashing up of the spring drive to the propeller. Glycol Cooling. One of the troubles is the big reduction in the effective octane value at high temps. - i.e. detonation on the Curtiss Conqueror. There is also a big drop in vol. efficiency after 240°F.{Mr Friese} and the operating temp. has been reduced to 230°F.{Mr Friese} from mechanical considerations. They have not had any piston trouble since going to the 'waffle plate' design. (I have a lot of further information on Glycol Cooling from Wright Field which I will deal with later). Direct Injection - General. Direct injection is making rapid progress and receiving considerable attention. The air line which has tested it for over a year is very keen on it. They have got away from their previous freezing troubles and obtain wonderful acceleration and snap opening even with a cold engine. Valuable when gliding down from high altitude. The system used on the Western air line is external injection and Bendix are busy developing this system into a simple unit production form. | ||