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A test technique to monitor the quality of the fuel in terms of injector nozzle deposit formation has been developed. Injector nozzle deposit is accumulated by fitting injectors to a bench mounted production engine coupled to a dynamometer. The engine is operated according to a simple run/shutdown duty cycle. At the termination of the test, the effect of the deposit on the flow characteristics of the injector nozzles is established. In the case of an intermittent type of injector, the flow is measured. In the case of a continuous type injector, the spray pattern is evaluated.

Motor racing in general and Formula 1 in particular, represents the leading edge in automotive technology. Participation in Formula 1 presents a challenge and an opportunity to the petroleum industry, where significant research benefits can be gained in terms of product development. As a direct result of the regulations governing the composition of the fuels that may be used in motor racing, especially in Formula 1, they have much in common with their commercial counterparts. Racing fuels and lubricants are however optimised for the specific demands of motor racing. The technology gained through this research has had a significant bearing on the procedures and equipment employed in commercial fuel and lubricants development. Because of the very high specific output of a modern racing engine, the fuel evaluation procedure is vastly different from that used on commercial engines.

Ignition-improved methanol can be used as a fuel for heavy-duty diesel engines. However, endurance tests have revealed several fuel-related durability problems. Serious cavitation-induced erosion was observed in the injection system and extremely hard ceramic-like combustion deposits caused significantly increased wear. Since solutions could be found for most of the problems encountered, the technical viability of ignition-improved methanol can be considered as sufficiently proven. However, further development work will have to be done to modify engine parts and materials and to adjust properties of lubricating oil to the requirements of operation on methanol fuel.

A fuel blend containing 20% so-called ‘propanol-plus’ and 80% SASOL diesel was tested in a 4-cylinder direct-injection diesel engine. The propanol-plus, a mixture of 47% propyl alcohol and 53% higher alcohols, is a by-product of the SASOL fuel-from-coal process, and it would be of tremendous advantage if it could be blended ‘on-the-spot’ with the diesel produced by SASOL. Performance results with standard injection pump settings indicated that in comparison with operation on pure diesel, operation on the propanol-plus/diesel blend reduced the power by roughly 5% throughout the speed range. In addition, the volumetric fuel consumption was increased by, on average, 5.5% throughout the speed and load ranges. Despite the harsh combustion conditions created by the poor ignition quality of the propanol-plus/diesel blend, the engine successfully completed 300 hours of a particularly severe durability cycle.