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).
Test report on the condition of various engine components following a mileage run.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan291 | |
| Date | 1st September 1970 guessed | |
| - 2 - Pistons, fitted with new Brico unlapped piston rings. Towards the finish of the test there were slight piston knocks when starting up when engine was cold. These disappeared immediately the engine became warm. The amount of carbon on piston heads is not more than normal for the mileage run. The bedding of the pistons is none too good. Distortion has apparently taken place. The gudgeon pins shew signs of rubbing hard on both ends. We have not noticed any gudgeon pin knocks, & all gudgeon pins were tight in their housings when examined. The piston rings were free in their grooves. The scraping action of rings has been lost, due to the rings having worn oval on the face of rings. This is apparently the cause of the increase in oil consumption towards the end of the mileage. Examination of pistons, immediately after runs, did not shew excess of oil on tops of pistons, the oil having been apparently burnt away during high speeds. We ran our usual fifteen minutes slow running at close of mileage & the exhaust remained clear. It was also clear when engine was raced up. Ignition plugs. "Ledge" detachable 200 type. These plugs were fitted in Derby, & have run considerably over the mileage. We have not had any trouble with the plugs throughout the test. On one occasion only did they shew signs of being damp with oil. Examination at finish of mileage shewed them to be slightly carboned up round the bottom edge, the points remaining clean & dry. Very little burning effect of points has taken place. Periods. These have not altered during the running of the car. There is still one between ten & fourteen m.p.h. which causes controls in steering column to rattle, but we do not consider this more than normal. The retard period from 50/40 m.p.h. has remained much the same. There have been occasions when it was more pronounced. Engine gears. These have improved slightly during the run. There has been no sign of rattles, & the gears are in good condition. Engine case. This has remained in good condition generally. The oil leak reported from water pump drive is still there. We dismantled this, & on taking the ball race thrust housing down, we found it full of oil. It is evident that too much oil is getting through the ball race, & does not drain away sufficiently through the holes provided. We are endeavouring to find the cause and cure this trouble. Water pump & drive, to L.O.P. E.70527. The water pump is fitted with standard Lion packing. The water pump has functioned satisfactorily during the test. We have had no rattles from the drive, which upon examination we find to be sufficiently lubricated, & this is in a good condition. No wear can be noticed in bearings of water pump. | ||