Letter discussing Cadillac's adoption of a vacuum pump for their fuel feed system and a wider trend away from using intake vacuum for accessories.
| Identifier | ExFiles\Box 40\3\ Scan068 | |
| Date | 16th September 1927 | |
| S/W {Sales / Derby Works} HS {Lord Ernest Hives - Chair} X3575 Oy10-E-91627 September 16, 1927. Mr. F. {Mr Friese} H. {Arthur M. Hanbury - Head Complaints} Royce, Rolls-Royce Ltd., London, England (Copy for attention of Mr.Hives " " " " Mr.Haldenby) Dear Sir: re Vacuum Feed We wish to draw your attention to the fact that Cadillac, in their latest publicity, announce the addition of a vacuum pump as a supplement to the intake vacuum for operating the fuel-feed tank. We have not seen the installation but I imagine it means that the discharge from the pump runs to the intake pipe, which would be the neatest way of disposing of fuel vapor from the vacuum tank. There is widespread dissatisfaction with the vacuum feed amongst American manufacturers. Hence the development of such devices as the "Autopulse" electric fuel feed, the A-C engine-driven fuel pump, Kingston "Oil-Vac" system, etc. There appears to be a revulsion against using the intake vacuum for anything, so that vacuum windshield-wipers are being replaced by electrical wipers, etc. It is significant that Cadillac, which was the last American car to abandon air-pressure, is the first to make improvements on the vacuum feed. We imagine that they will use a double-ported pump which will work without valves, similar to their old pressure-feed pump. See attached sketch SK-105. | ||
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).