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 condition of bearings, carburetters, ignition systems, and radiator fittings after extended mileage testing.
| Identifier | ExFiles\Box 101\2\ scan0232 | |
| Date | 1st January 1937 | |
| -3- The bedding in each case extending over the whole bearing surface, with the exception of Nos. 2 and 4 bearings, which showed a bedding more towards the centre, but in no case showed signs of bad deterioration. The crankshaft pins were found to be smooth and free from scores. The main bearings were in a poor condition throughout, Nos. 2, 3, 4, 5 and 6 showed signs that the white metal had partially run into the oil grooves forming a restriction. There were also holes in the bearing surfaces, but not of sufficient magnitude to permit of any loss in oil pressure. The journals were found to be smooth and free from scores. Since running with this oil we have had no trouble with the bearings. The big ends have completed 26,000 miles, and have been, approximately, 4,500 miles since "Arctic" oil was used. CARBURETTERS. (Stromberg - Standard Production). We have had no serious trouble with this unit. We have complained in our daily reports of occasional popping in the air silencer when the throttle pedal is fully depressed. This popping cannot be reproduced to order. We have not been able to trace the cause of this popping, as it only occurs once every 50 miles or so. IGNITION. The KLG. 850 plugs which had run, approximately, 13,000 miles were removed, and Champion LB.10 plugs were fitted. These are porcelain insulated, and were fitted with the object of overcoming misfiring which is prevalent with these plugs. We have had no trouble with these plugs and they have completed a mileage of 7100. Idling with these plugs was rythmatic and even up to 6,000 miles, but at that mileage the idling had an uneven tendency, although the pick-up remained smooth and free from misfires. The gaps had altered from .018" - .022" during the mileage and subsequently altered to .023" at the conclusion of the test. RADIATOR FITTINGS. LOP. E.56831. The fabric tape round the radiator edge on which the bonnet rests has worn right through in one place, and the bonnet rests is rubbing on the angle brackets on which the tape is fixed. This has set up a thumping whenever the radiator moves. | ||