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).
Engine component issues including crankshaft rattle, valve clearances, piston knock, and ignition plug failures.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan233 | |
| Date | 2nd May 1929 guessed | |
| -2- A crankshaft period at 40 M.P.H. developed after approximately 4,500 miles and became very noticeable. At the same time there was also a spring drive rattle at a speed of 25 M.P.H. We reduced the crankshaft period by 50% and the spring drive rattle by 90% after reducing the damping load on the spring drive and resetting the slipper load to 10 lbs. CYLINDERS TO LOP E 77651 - Sch IIOI - 2 - LEC 2651 We examined these from underneath, the cylinder walls appeared to be in good condition and free from any score marks. The walls were well lubricated. Tests carried out previously, slow running for 15 minutes did not show any signs of over lubrication. VALVES AND FITTINGS TO LOP E 77652 - Sch IIOI ROCKER SHAFT TO V 453 ROCKER ARMS FITTED WITH RESTRICTION PLUGS TO V 410 VALVE SPRINGS TO E 78071 We have not had any serious trouble with the valves but the valve clearances have not remained as constant as on previous test. We found that most of the clearance had been taken up in the exhaust valves after one or two long sustained runs. The clearance had altered from .006" to .000" and .001". No 1 and 2 exhaust giving the most trouble. The rocker shaft and bearings have had ample oil. One plug has come out of EB 1 exhaust rocker arm. There is a slight valve spring period but it is not objectionable unless there is excessive clearance. The warming up period is noisy. CRANKCASE AND BEARINGS TO LOP E 78560 - LEC 2631 - 2655 With the exception of a bad oil leak from the rear of the crankshaft we have had no trouble and cannot see any defects in the case. Bearings have not been examined. PISTONS TO LOP E 78563 WITH PERFECT CIRCLE SCRAPER RING ABOVE GUDGEON PIN When cold No 1 and 5 knock very bad, we also suspect gudgeon pin knocks. The knocks disappear after engine has warmed up. We have had no signs of pistons overoiling. Piston squawks were noticeable at the beginning of the mileage after a hard run. These disappeared and have not since been heard. LODGE DETACHABLE IGNITION PLUGS. We have had three failures due to cracked procelaines. | ||