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 results of testing Aero Shell lubricating oil in car engines.
| Identifier | ExFiles\Box 179b\3\ img342 | |
| Date | 16th March 1933 | |
| ORIGINAL To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} c.c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c.c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c.c. Ry. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}1/KT.16.3.33. Re. AERO SHELL LUBRICATING OIL FOR CAR ENGINES. Aero Shell lubricating oil has been tested on Expl. Dept. cars as follows - (1) 18.G.IV., 10,000 miles in France concluded in Jan. 1931. (2) 25-EX., 25,000 miles in France concluded in Oct. 1931. (3) 25-EX., 23,700 miles in England concluded in Dec. 1932. It is advisable to give a brief resume of the results of the tests in the first two cases. (1) The engine in 18.G.IV. was stripped at the conclusion of the test and it was found that the crankshaft main bearings and journals were in a bad condition. Apart from this the general lubrication of the engine was satisfactory. Following the examination of the engine considerable controversy arose as to whether or not the condition of the main bearings was due to the oil used. After investigation in several quarters no definite conclusion was arrived at, and it was agreed to test this oil on the next car going to France. (2) The engine in 25-EX when stripped for examination revealed a broken centre main bearing cap and retaining stud. In addition a certain amount of metal was broken away on the cap halves of Nos. 3 & 5 main bearings; these failures were not attributed to the oil. The big end bearings and the crankshaft journals were in good condition. Oil deposits in the inside of the crankpins were reported as filling up the bore approximately half way. The remainder of the engine was found to be in very good condition as regards the effects of lubrication. The oil deposits were removed from the bores of Nos. 2 & 5 crankpins and the deposit sent away for analysis. A doubt was raised at the time that the crankpin deposit was excessive, and it was thought possible that after a greater mileage it might increase sufficiently to cover the oil feed holes. Shell-Mex people were of the opinion that this would not increase with further mileage owing to the fact that with increasing mileage the deposit gets denser and eventually reaches a condition where very little more sludge adheres to it, because the oil velocity rises, due to the restricted | ||