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).
Faults found after 9,000 miles, detailing oiling problems on the front axle and issues with exhaust valve clearances.
| Identifier | ExFiles\Box 5a\2\ 02-page226 | |
| Date | 20th March 1930 | |
| Handwritten notes: Top Left: To: ER. From O.A.S. Top Middle: By YSWPA maled By DA{Bernard Day - Chassis Design} noted on E noted [initials] Top Right: Return H.S Hôtel de France, Chateauroux. Right Margin: 50/H/30 Left Margin (vertical): The points under this letter up to date are the only faults that have developed up to 9754 miles - J.E.L. Thorpe Margin next to paragraph 2: started Typed Document Body: 20/3/30 18/3/30. We have to-day received your letter H83/W. As we finished our 9.000 miles yesterday afternoon, we started to attend to some of the faults that we have found out, before receiving your letter. One of the faults we have run up against is the choking of the oiling scheme on the front axle. As reported to you, the o/s front ball and steering arm had become dry. To-day we have investigated the cause of it. One reason was that the bijur was not passing sufficient oil when tried on a separate tank. We changed this and got this bijur working correctly on a separate pipe line. then fitted it into the system for feeding the o/s ball and. We applied the gun before finally fitting up, and found that again no oil was passing. Therefore, we took the various bijurs down, and found that no oil was passing through the pipe line at all. Upon investigation, we found that the felt out of the Knots nipple had become lodged in the feed hole in the axle, to the pivot on the o/s, which is nearest the Knots. Examination of the Knots lubricator disclosed that the copper mesh holding the gauze had given way and allowed the felt to go through with the pressure of the oil. It must be understood that no undue pressure had been used on the Knots gun. It is of the present standard type, therefore we cannot attribute the failure of the felt to any high pressure. We have had to dismantle the whole of the pivot to get this felt out, which we are enclosing to you along with a sketch showing exactly where we found the felt. As the exhaust valves, we have got some data to go on, but not very much. we found that after 1600 miles one exhaust valve had lost .004” clearance, but up to the present we cannot say where this clearance is going. The question of a few thous. stretch on a valve is difficult to measure over here. we have carried out tests and found that the clearance of the valve increases .002” when hot. The valve that had lost its clearance had been set to .004” dead cold, and when hot was .006”. Therefore it looks as if the trouble of the burning is due to the valves at some time or another being on their seats. We are making a guage so that we can accurately get the reading of the height of a valve in the cylinder head, irrespective of the rocker mechanism. We shall then be able to tell whether the valve has come up higher and taken up the clearance definitely. There are so many snags in checking up valve clearances in the ordinary way that one can be easily misled. We hope within the next week to be able to give you some definite figures to give you, as we have to-day sent you one exhaust valve taken out of the engine. ................... | ||