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).
Use of special oil pumps and vacuum systems, with reference to Cadillac and Stewart systems.
| Identifier | ExFiles\Box 40\4\ Scan173 | |
| Date | 22th December 1925 | |
| Oy4-E-122225 -3- December 22, 1925. To do this they use a special form of oil pump, or in the case of cars with pressure feed pumps, they reverse the connections on the air pump. Cadillac are testing this device using their existing feed pump with reversed connections. The Cadillac pump is used for vacuum without any valves, as they have a "ported" piston which acts as a slide valve for both intake and exhaust. We suggest that in case of using the pump for vacuum this would be a desirable change. We have not used the Kingston "Oil-Vac" system because the Stewart gave such satisfactory results. The intake-suction systems have, we believe, an advantage over any systems using a "limited" vacuum, since on cranking the engine the vacuum tank is immediately filled. Thus, in case of the carburetter having flooded and the gravity supply leaked away overnight, or in case of running out of fuel, the supply is replenished as soon as the engine is turned over by the starter. Yours very truly, Maurice Olley MO/E | ||