About Laboratory Engine Test Procedures of Marine Lubricating Oils

Abstract

In recent years high alkalinity oils has been used in marine diesel engines, operating on residual fuel with high sulfur content. In order to evaluate the engine performance of these oils on the laboratory engine tests, several types of engine tests were discussed. The results were obtained as follows:
(1) Although a thermal loads of the diesel engine were highly, standardised laboratory diesel engine tests such as Caterpillar 1-A, 1-D, 1-G and petter AV-1 were found to be unsatisfactory for the evaluation of high alkality oils of which base numbers excess about 13 mg·KOH/g.
(2) Research was then done towards a type of small diesel engine using heavy fuel. Yanmar NK 3 engine test gave poor results. However, it was able to evaluate the detergency and antiwear properties of high alkalinity oils under 30 mg⋅KOH/g base number on Yanmar F4 engine having higher thermal load (0.117 bhp/cm²) than Caterpillar 1-A.
(3) For further inspections, the Bolnes engine test described by Pouderoyen et al. were checked. Bolnes long-term tests of oils with these numbers of about 0 to 70 could-be evaluated by measuring cylinder liner diameter increase and piston deposits rating, respectively, after continuous operation for 500-800 hrs.
Bolnes wear performance tests (Screening tests) could rapidly be evaluated the antiwear properties of high alkalinity oils. The authors discussed then a reasonable arrangement of the data.