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).
'F' cylinder tests focusing on oil consumption.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan028 | |
| Date | 16th December 1930 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. ORIGINAL. c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. Rg.{Mr Rowledge} EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/ACL1/AD16.12.30. x3866. "F" CYLINDER TESTS - OIL CONSUMPTION. In our last report on "F" cylinders (see Hs{Lord Ernest Hives - Chair}/ACL/AD6.12.30) we summarised the results in saying that the combination of :- increased clearance between liners and blocks, reduced foot, raised rubbers and pistons with scraper ring above the skirt, gave appreciably better results than standard with regard to elimination of score marks at the liner base. In our latest test we have fitted the engine with a complete set of pistons having the scraper ring at the top of the skirt and using the perfect circle type ring with .080 oil groove. The object of the test was to see what effect the raised scraper ring had on oil consumption particularly at high speeds. We know that the most efficient place for the scraper is at the bottom of the piston to give good oil scraping, but it is bad for cold starts before a plentiful oil supply reaches the cylinders. The engine was run for 4 hours at 9/10ths rated power at 2250 R.P.M. and one hour at full throttle 2700 R.P.M. The results were :- 9/10ths. 2250 R.P.M. 440 B.H.P. Oil Con. = 3 pts/hr. F.T. 2700 " 593 " " 7 1/2 pts/hr. Oil inlet temperature 63°C and pressure 66 lbs/sq.in. These consumptions are surprisingly good and as good or even better than the average standard engines with the plain scraper rings at the bottom of the piston. The fact that we have used the modified liner schemes on this test giving less distortion, we think may contribute to the low consumption. | ||