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).
Plunger clearance, oil leakage, and sludge issues in tappet and valve mechanisms.
| Identifier | ExFiles\Box 158\4\ scan0190 | |
| Date | 29th October 1937 | |
| -2- indicates that our plunger clearance is not entirely wrong. Furthermore, we have slightly increased the leakage factor since the tappets originally came on production. It is, however, quite conceivable that in customers hands the filters do not get cleaned as regularly as they do on our experimental cars, and that in consequence sludge may cut down the leakage factor to the danger point. We should, of course, expect this with Price's oil. There is no doubt that if customers could be induced to change to thin oil in the Winter, the chance of the trouble occuring would be reduced. It is particularly noticeable when cars are started up from cold. We should like Cricklewood, where possible, to check up P.III's when they come in by means of a cold start. If, under these circumstances, it is found that the valves are being held open, then a check should be made to see if this situation persists after the valve mechanism has been thoroughly cleaned. It may be that Cricklewood will be able to state on the condition of the valve gear on the cars which have had trouble that sludge cannot have been present, and in this case suggestion 2 could be dismissed. We know that the tappet mechanism will function satisfactorily under existing conditions with clean oil. Rm.{William Robotham - Chief Engineer} | ||