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).
Engine oil dilution and the function of the Clifford and Skinner oil rectifiers.
| Identifier | ExFiles\Box 40\3\ Scan026 | |
| Date | 18th September 1925 guessed | |
| is formed in minute quantities during the cycle or motor operations and finds its way to the crank case. The amount of dilution varies with different cars. In some American cars it is advisable to change the oil every 300 or 400 miles. Even in some high-class English and Continental cars the lubricating oil becomes very thin. The amount of petrol present in lubricating oil from a motor which has run a few hundreds of miles is surprising. The elimination of these diluents from the lubricating oil can be accomplished by constantly distilling the crank case oil at a controlled temperature and this is effected by the Clifford Oil Rectifier which is a simple, inexpensive automatic device easily fitted to a motor without interfering in any way with the design or lubrication of the engine. A 27 h.p. Buick car fitted with the Clifford Rectifier has run 35,000 miles with one change of oil and is still running perfectly on the same oil and recent tests show the oil to have lost practically nothing of its original viscosity. Other types of cars have been tested with equally satisfactory results. Although there are several devices on the market for cleaning oil of solid contamination and for diminishing contamination, it is a virtual impossibility to maintain oil in a motor vehicle entirely free from contamination with solid matter. Such contamination is not a serious matter so long as the oil is maintained at a good degree of viscosity. Hence we find many old cars still running well, because they have been well looked after and the lubricating oil regularly changed. If the oil is maintained at a proper degree of viscosity such contamination from solid matter as now takes place is not a serious matter; but if the oil is allowed to become thin then abrasion takes place and trouble follows. Apart from the waste of oil necessitated by frequent change the advantages to be derived from maintaining lubricating oil at a fixed viscosity and that the best suited for the particular motor, are obvious. As long as the viscosity is that best suited for the car and remains constant at that, the motor will deliver maximum power at a minimum fuel consumption, and repair expense. There is now an apparatus on the market for rectifying crank case oil in a motor vehicle, and is known as the Skinner Rectifier. This apparatus is at the moment fitted to some American cars. Its function is to remove diluents from the oil before they can enter the crank case by withdrawing oil from the cylinder walls above the crank case. If too much oil is so withdrawn there is obviously the risk of lubrication trouble. To fit the Skinner Rectifier a more or less complete re-design of the motor is necessary and the device is necessarily somewhat expensive. THE CLIFFORD RECTIFIER is an inexpensive and simple apparatus, requiring no alteration of the motor. It rectifies the oil by distilling from it petrol and water vapour. The operation is continuous whilst the motor is running and so the viscosity of the oil is maintained. The oil is taken directly from the crank case and returned to the crank case after the distillation without interfering with the lubrication of the motor. It completely removes diluents from the oil and does no injury to the oil. The Clifford Rectifier consists of a hollow metallic tube (1)* inserted in the exhaust manifold so as to be subject to the heat of the exhaust gases. The metallic tube is filled with the motor lubricating oil and contains submerged in the said oil a specially designed bellows type of thermostat (2) which assumes the temperature of the oil contained in the tube. * NOTE.—These figures refer to illustrated sketch which follows on page 7. | ||