Erratic exhaust valve clearances after a 300-mile run and proposed changes to water temperature reporting.
| Identifier | ExFiles\Box 11\3\ 03-page452 | |
| Date | 24th July 1931 | |
| 82941. To Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} From G.W.H. Hotel de France, Chateauroux(French test region), FRANCE. 24.7.31. 25-EX. Re. Exhaust Valves. We set the exhaust valves .010" clearance with the exception of No.1. The clearance after 300 miles was as follows :- | 1 | 2 | 3 | 4 | 5 | 6 | | |---|---|---|---|---|---|---| | .006 | .010 | .010 | .010 | .010 | .010 | as set | | .006 | .007 | .006 | .002 | .007 | .010 | after mileage | | .000 | .003 | .004 | .008 | .003 | .000 | lost clnce | It will be seen that the results are very erratic. We are therefore changing the valves in No.2, 3, 4, 5, & 6. No.1 is a new valve, before we again try any different settings, as apparently there is some feature which is not consistent. I reported to you yesterday that there may be some change taken place in the material that the valves are made of. We certainly had better results when we first tried the SSLV as against the crown steel valves. There is also the probability that with the distortion of the valve seat there is not sufficient contact of the seat to obtain the cooling effect. We should be pleased to have your views on the subject. Re. Water Temp. We shall in future state on the report sheets, the average water and air temperatures for the morning and afternoon's run, as we find that the cooler atmosphere, early morning, makes the average lower than it should be. We had during yesterday's afternoon, ran on an average water temp. of 91.8°C with an air temp. of 31.8°C. There was a short distance run when the water temp. reached 102°C. This was with a following wind. These results are with the large tube radiator. G.W.H. | ||
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).