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).
Various component issues including piston failure, a noisy spring drive, and poor running caused by the induction pipe.
| Identifier | ExFiles\Box 5a\2\ 02-page045 | |
| Date | 6th July 1908 | |
| PISTONS TO LOP. R85113. NEW SET OF PISTONS S55108. We suspected the pistons of having become faulty during the running and causing the excessive crankcase pressure. We found, when these were taken out, that on 3" 1 piston the second ring from the top had broken approx. .685" from one end. The broken portion had embedded itself in the groove and had gradually bored a hole under the two lower rings. Also on this piston the whole piston ring stop had broken off close to the bottom of the ring groove. The pieces fell out when the piston was taken out of the engine. This explains the high crankcase pressure as a considerable amount of gas was blowing through. There was no sign of this fault on the remaining pistons and all rings were free. The bedding of the pistons was good. 3" 1 piston knocked when cold. There was considerable amount of carbon on the piston heads. The gudgeon pins were well lubricated and showed no signs of wear. There was no sign of over oiling when running slow. CONNECTING RODS TO LOP. R 85136. "E" RIGIDION IRON. The connecting rod bearings were in good condition, there was no sign of any failing of the metal. CRANKSHAFT TO RUM. STANDARD SPRING DRIVE 1.750 DIA. CRANKPIN. This from an outside examination was in a good condition. SPRING DRIVE N 53750. STANDARD TYPE. The spring drive became very noisy during the run. It was very bad for chunking when picking up from slow speeds. When examined, we found the load of the slipper wheels had come up to 11 lbs. and upon dismantling the wheels we found that one of the cotton duck washers had become jammed between the hub and the wheel. These cotton duck washers could not be a standard size when fitted, as the diameter of the inner circle was much too large. We have not had this occur on any of our standard slipper wheels. The load on the slipper wheels using these cotton ducks could not be got down to 7 lbs. without taking half the springs out. The spring drive friction plate was jamming on the spigots, and did not allow an even load for the spring drive. This was corrected and after re-erecting the complete slipper wheel, the roughness and chunking was overcome. IGNITION PLUGS. It would be an advantage if more clearance could be given for the plug box-spanner. There is at present hardly sufficient room to take the plugs out easily. INLET PIPES Lcd 5871. INDUCTION PIPE, JACKETED. ROLLS R54906/7/8. The carburation is very susceptible to the water temperature. When starting up from cold, there is a considerable time elapsed before the engine can be opened up. The slow running of the engine is not particularly good with this induction pipe, and petrol consumption is on the high side, i.e. our average consumption being 14.96 M.P.G. The carburettor will not stand any weakening of the jets. In dismantling the induction pipe we found that it was not very accessible, the chief faults being the nuts fastening the water pipesto the water jacket. The leverage of the carburettor throttle opening per notch on the quadrant is too high and makes too much difference in the speed of the engine. This may be the chief cause for poor slow running. There are no signs of failure of the inlet pipe. | ||