LABORATORY ENGINE TESTING OF MARINE DIESEL CYLINDER LUBRICANTS

The above is the title of a paper by A. J. S. Baker and R. T. Davies (Esso Research Ltd.) presented to The Institute of Petroleum on 13th November in London. They pointed out the need for a suitable engine to test lubricating oils for marine diesel engine cylinder use. A two cylinder Bolnes engine was used having a 7.5 in. bore and 13.8 in. stroke, run under test conditions of 37.5 bhp/cylinder and 430 r.p.m. Lubricant was delivered to the working cylinders by sight feed lubricator, two feeds per cylinder discharging through open‐ended quills into an oil distribution groove in the liner below the scavenge ports. The test fuel had a sulphur content of 3.74%. The first test procedure consisted of a continuous period of 500 hr. operation, with cylinder oil fed at the rate of 1 g/bph/hr.—a rate recommended by the engine maker. Wear rates were higher than those obtained on engines at sea, but they provided a correct reflection of field performance.