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).
Carburation irregularities on the 40/50 HP model when the Autovac system is working.
| Identifier | ExFiles\Box 66a\1\ scan0209 | |
| Date | 16th January 1928 | |
| S/W.EP.{G. Eric Platford - Chief Quality Engineer} Copy to:- Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} PN.{Mr Northey} H.{Arthur M. Hanbury - Head Complaints} Hs.{Lord Ernest Hives - Chair} X8080 CWB12/GM/16.1.28. Re: 40/50 H.P. IRREGULARITIES IN CARBURATION WHEN AUTOVAC IS WORKING. It has recently been noticed that cars vary considerably in the irregularity of running when the autovac is exhausting. Speaking generally, the situation is enormously improved by the addition of the special reducing elbow on the suction pipe and also in cases where the ball and roller bearings are fitted to the throttle and governor controls, but even in these latter cases there is a very large difference between car and car in this matter. Frith of the Inspection Department has recently had to deal with one or two cases of complaint from this matter and he has found that there is a great difference in the working of the reducing valve on different cars, and I have examined one or two with him and found that when the reducing valve is working freely the effect of the autovac exhausting is very small compared with the effect when the reducing valve is somewhat sticky. I am sending you by separate post 2 of these reducing valves which are not working properly, one of them quite new, and if the cap is taken off from the end while the car is at work it will be found that when the suction is closed the plunger in the reducing valve does not move fully home and when it is open its action is much more irregular than in the case of a good free working specimen. Would you please see in the case of all future cars passed off test that the action of this valve is observed to be perfect and free. I have no doubt that the cause of the two valves which I am sending to you not working freely and perfectly is a very trifling one and can be easily remedied by taking them apart, but I have preferred to send them to you exactly as tested with poor results here so that you may see the effects and then ascertain the cause of it at W. so that we may in future eliminate this cause, whatever it may be. CWB. | ||