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).
Promotional document explaining the 'Float-O' variable level oil intake system and its benefits.
| Identifier | ExFiles\Box 15\6\ Scan135 | |
| Date | 15th April 1931 guessed | |
| FLOAT·O ELIMINATES MANY ENGINE TROUBLES REDUCES REPAIR BILLS THE NEW VARIABLE LEVEL OIL INTAKE OIL PUMP [Left Column] The illustration above shows the intake system commonly in use at rest. The crankcase contents have settled into layers. Observe that only sediment and water surround the pump intake—the first material to be conveyed into the lubrication system. The illustration below shows the same system in operation. Sediment, water, solids and oil are completely mixed. The resultant mass is being constantly circulated through the bearing surfaces of the engine, causing undue wear. [Center Column] Many engine troubles that cause large repair bills are due to faulty lubrication. Scored cylinders and worn bearings are direct and obvious results of lubrication failure. Float-O is a movable oil intake which floats in the oil. It draws, therefore, from a point just below the top level. It is simple to demonstrate that abrasive impurities and water will sink to the bottom of a crankcase and remain there if not disturbed by pump suction. The universal practice in building engines which circulate oil from the crankcase has been to take the oil into the pump at a fixed point, usually a half inch or less from the bottom of the case or invariably in the contaminated zone. This low intake point has been necessary in the past to secure proper functioning when the oil is low or when, due to sharp turns or sudden brake applications the oil is likely to be thrown away from an intake placed otherwise. Float-O, the variable level oil intake, is not a filter. It operates on the principle of isolation rather than filtration. Its isolation efficiency is from 75 to 98 per cent depending upon the type of service. This efficiency is CONSTANT and applies to ALL of the oil circulated by the pump rather than a certain portion that may be by-passed through any cleaning element. Oil, water and solids will invariably settle into three well-defined layers. With an intake placed near the bottom of the case, the solid particles and the water will be drawn into the lubrication system first. [Right Column] In cold weather Float-O is of special importance for two additional reasons. First, the water layer frequently freezes and where the intake is in or below this water layer, circulation is totally stopped. Second, Float-O being movable has the ability to go to the oil when the oil cannot flow to it. This means that the lighter oils commonly used in winter to assure circulation need not be used in Float-O equipped engines. Float-O makes it possible to use oil of a proper body for lubrication at high operating temperatures that would be too heavy to flow to a fixed oil intake when cold. It is obvious that with the Float-O intake there is no possibility for air to become trapped and lock the intake system. Which takes place with fixed intakes on violent brake application, or sharp turns. | ||