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The development, evaluation, and selection of Plasma spray powder material for the coating of aluminum-alloy engine cylinder block bores was conducted to yield a bore system which provides numerous benefits relative to the present cast iron sleeve system. These include: a reduction in ring/bore wear, friction, and in engine oil consumption as well as a benefit in reduced corrosion. A reduction in engine weight, overall costs, and improvements in machining and honing operations are shown. Alternate thermal spray processes are also described in this investigation. Test evaluation leads to the selection of two plasma powder material spray systems. One system emphasizes low cost relative to the present system. The second system provides significant reduction in friction and ring/bore wear through the introduction of solid lubricant in the material composition.

Application process, and performance in engine dynamometer and high mileage vehicle fleet durability tests of Plasmaspray coated bore aluminum block engines are discussed. Fuel economy, oil consumption, power and wear data for Ford 4.6L-V8 aluminum block engines utilizing very low cost iron/iron oxide base coatings, and stainless steel/BN solid film lubricant Plasmasprayed coatings are presented. Test results from Ford's 100 hour Piston & Gasket Engine Dynamometer Durability Tests, and Fleet Vehicle Durability Tests show ring/bore wear reductions of more than 40% relative to production cast iron bore systems with Oil Economy averaging more than 13,600 km/l (8000 mi/qt).

An evaluation of engine valves made of solid ceramic materials for use in an uncooled DI diesel engine was conducted. Two candidate ceramic materials were chosen: yttria partially stabilized zirconia (PSZ) and sintered silicon nitride (Si3N4). The evaluation was undertaken in three phases. First, a finite element analysis (FEA) was conducted for both steady state and transient conditions. Then the finite element analysis results were used in a Weibull ceramic failure theory analysis which yielded predictions of the probability of failure of the valves. These predictions indicated that under severe analytically imposed cooldown conditions, the PSZ valve would have a probability of failure of 100%, whereas the Si3N4 valve experiencing the same conditions would fail less than two times per ten million. The final phase of the evaluation was conducted when valves were fabricated from silicon nitride and tested in an engine.

This paper presents an experimental technique for locating engine cooling system hot spots by using a Magnesium Borate water solution for the engine coolant. In doing so, Magnesium Borate is deposited wherever local boiling occurs thus indicating the high temperature areas. This technique was applied to a large V-8 engine and provided visual results of high temperature areas in the water jacket. Color photographs show the results, which correlate with measured metal temperatures and measured coolant flow velocities. The extension of the technique to include estimation of metal temperatures results from additional test data reported. The procedure is useful for locating unsuspected hot-spots in any passage in the engine cooling system. The severity of the temperature may be determined by knowing the Boiling Point of the solution.