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).
Letter from AC-Sphinx Sparking Plug Co. Ltd. discussing vapour lock issues and recommendations for re-routing petrol piping.
| Identifier | ExFiles\Box 27a\2\ Scan049 | |
| Date | 12th August 1931 | |
| TELEGRAMS: SPHINX, BIRMINGHAM. TELEPHONE: MIDLAND 1742 (2 LINES) PRIVATE BRANCH EXCHANGE. THE AC-SPHINX SPARKING PLUG CO. LTD. DIRECTORS: N. F.{Mr Friese} STOCKBRIDGE, B. C. MUGGLETON. BRADFORD STREET, BIRMINGHAM. OUR REF. NFS/NA.{Mr Nadin} YOUR REF. August 12th 1931. Messrs. Rolls Royce Ltd., DERBY. Attention of Mr. Hancock. AC PETROL PUMP. Dear Sirs, With reference to Mr. Hancock's telephone conversation with the writer concerning vapour lock trouble experienced on the car to which was fitted one of the AC Petrol Pumps which we sent you some time ago, we have previously had very little experience of this trouble on other installations. We are inclined to think that the trouble is due to the petrol piping from the rear tank to the pump being exposed to heat radiated from the exhaust manifold and exhaust pipes, as well as the heat reflected from the road, and that this trouble is aggravated by the length of the piping from the tank to the pump, which in the case of your installation is probably greater than average conditions. Without examining the exhaust piping and petrol piping on your chassis it is difficult for us to make any recommendations, and under the circumstances we recommend that the petrol piping should be run back to the tank on the opposite side of the frame to the exhaust piping. It is also advisable to attach the petrol piping to the frame side member in such a manner that the air can circulate around it, except at the points where it is held by the clips. Whether it is advisable to mount the petrol piping below the bottom flange of the frame side member or inside the top flange, depends on whether the trouble you are experiencing is due to heat reflected from the road or heat reflected from the exhaust piping. It would seem that in the former position it is more likely that you would get air circulating around the piping and so keep it cooler, but whether it would be advantageous to move it to the inside position is a case for experiment. Vapour lock trouble is frequently accentuated by heat imparted to the petrol by reflection from the road to the bottom of the. MAKERS OF AC SPARKING PLUGS - AC AIR CLEANERS - AC PETROL PUMPS - AC OIL FILTERS. Handwritten: E C Gd A 82677-Copies sent 17/8/31. wm/9. P. | ||