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).
Report discussing varnish formation on bearings, oil refining improvements, bore finish, and aircraft diesel engine technology.
| Identifier | ExFiles\Box 178\2\ img046 | |
| Date | 30th March 1940 | |
| Design Page 80 Serial No. 80 CY 1/5/Mar.30.40 Symposium on varnish formation sent you with my January S.A.E. report. Corrosion of cadmium bearings is also a function of temperature. The Ford is particularly good for temperature, because of long jackets and perhaps partially due to the fan on the crankshaft. Fishbone suspension and projecting sheet metal have contributed to high temperatures in the oil pan. Also, any improvement in riding and handling which inevitably leads to harder driving. At the same time, it is historically true that the oil companies did produce varnish conditions by super-refining their oils. Vacuum Company avoided it and the Texas company has cured the condition by putting the varnish inhibitors back in the oil. Best authority on this is G.M. Research because of their oil testing program of which I have sent you details. Bore finish has nothing to do with it. In fact, except for the examples of nitrided bores already sent you, no one appears to have succeeded in avoiding ring seizure when bore finish goes beyond a certain standard of smoothness. (d) Aircraft Diesels Cooling of pistons and spark plugs and getting the valve gear to work twice as frequently as it does now, are always mentioned as the chief troubles on 2-cycle engines. The first is being cared for by damming heat-flow to rings and putting all possible heat into skirt, then flood-oiling the lower side of the head and inside of skirt. The second is absent with a diesel. The third sounds like an imaginary trouble to me, unless spring surge is worse on 2-cycle engines. I don't believe I have reminded you about the papers on the Curtiss scavenging system developed at Westinghouse which Lessells sent to Elliott. I believe about a year ago. The assumption here is that 2-cycle scavenging demands a "uniflow" system like the G.M. diesel in which firing charge is blown in at bottom of stroke and a flock of exhaust valves are mounted in the head. Lessells, quoting Westinghouse experience, doubts this very hard. Enclosed are two prints showing diagram of scavenge system and photo of cylinder liner. Elliott has much information on this. Heron I find skeptical about the 2-cycle development in any form. Finds nothing yet in this country which promises anything like the H.P. per cubic inch which 4-cycle engines are giving, and doubts its ability to speed up its cycle and thus meet 4-cycle competition. Speaking of speed up reminds me that I have lost the | ||