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).
Troubleshooting a rich fuel mixture issue caused by the autovac system.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan15 | |
| Date | 4th July 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF: HS{Lord Ernest Hives - Chair}2/LG4.7.25. C which is used on the Hispano; this has the same fault. We have tried connecting the autovac to different points on the induction pipe. We have not been able to make any noticeable improvement. We think that this is due to the fact that the rich mixture which comes from the autovac is in the form of a gas, it is therefore distributed to all cylinders. We have also taken this matter up with the makers. Attached is a copy of a letter in reply dated 3rd. July! It is agreed that this action of the autovac has a greater affect on some cars than others. In order to reduce the effect to a minimum, the low speed jet should be set to the minimum to obtain even slow running. Care should be taken that the distribution is as perfect as possible. At low speeds, with small throttle openings, there should be very little trouble with distribution owing to liquid petrol but there is likely to be trouble if the inlet valve guides have worn to any extent. The sparking plugs should be clean and the points set correctly. We are still continuing our experiments! Hs{Lord Ernest Hives - Chair}! | ||