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The friction characteristics of several DEXRON®-III automatic transmission fluids were examined in a variety of friction tests. These evaluations included tests with SAE No. 2 Friction Machines using either Band or Plate heads, breakaway friction tests, and low-sliding speed friction tests. The effect of bulk fluid temperature on friction performance was examined in band tests and in breakaway tests using the plate clutch apparatus. The DEXRON®-III fluids were compared to the previous generation automatic transmission fluids. Results showed that the DEXRON®-III fluids exhibited more desirable friction characteristics; for example, with the DEXRON®-III fluids in the band machine, dynamic friction remained stable during sustained operation at high temperature, whereas with DEXRON®-IIE fluids, dynamic friction decreased as much as 25%.

Frictional characteristics of several automatic transmission fluids (ATF's) were evaluated in an SAE No. 2 Friction Machine adapted to the band clutch from a front-wheel-drive, three-speed automatic transaxle. The bench test apparatus subjects the band clutch to repeated engagements (24 000 in a 100-hour test period) at elevated temperature with representative clutch energy dissipation and lockup time, and with forced aeration of the fluid. Fluid frictional performance is judged from the level and stability of friction torque during the 24 000 clutch engagements. The test is repeatable and readily distinguishes fluids having different frictional characteristics. Fluid frictional behavior in the band machine is shown to reflect fluid effects on shift performance in an engine dynamometer, transaxle cycling test. Also, fluid effects determined in the cycling test are shown to match those obtained in a vehicle.

The process of deposit-induced, fuel-flow reduction in multiport fuel injectors of the director-plate type was investigated both experimentally and analytically in order to understand both the flow-reduction mechanism and the non-linear variation in flow reduction with engine operating time. Injectors that had accumulated deposits in previous extended engine testing utilizing a rapid-plugging fuel were flow-tested, and the orifice plates from two of the injectors containing deposits were examined using a scanning electron microscope. A thin, carbonaceous deposit protruding into the flow paths of the orifices was found to be present on the downstream face of the orifice plate, but not present within the fuel orifices or on the upstream surface of the plate. Based upon these observations, calculations were made using a fluid flow model of an orifice plate with deposits.

An engine dynamometer test procedure was developed for evaluating fuel and fuel additive effects on the plugging of port fuel injectors. The test procedure was shown to adequately reflect the influence of fuels and additives on injector plugging in vehicles. Injector soak temperature and fuel system configuration were found to be critical factors in obtaining an acceptable engine-vehicle correlation. Injector plugging occurred in as little as 10 hours with a high-olefin base fuel; in contrast, plugging took two orders of magnitude longer with a high-quality, detergent-containing, commercial-type fuel. Furthermore, fuel additives greatly increased plugging resistance with the OEM, pintle-type injectors. Injector design alterations were also shown to be important. Pintle-type injectors with flared, aluminum caps extended plugging time considerably relative to the same injector design with plastic caps. Director plate-type injectors were much better still.

Methanol, a popular alternative fuel candidate, can theoretically be dissociated on-board a vehicle into a 2/1 molar mixture of hydrogen (H2) and carbon monoxide (CO) having a 14 percent greater heating value than that of methanol vapor. In this study, engine efficiency and fuel consumption with methanol vapor and dissociated methanol (simulated by a 2/1 mixture of Ha and CO) were compared in a single-cylinder engine at equivalence ratios (Φ’s) ranging from 0.5 to 0.9 and compression ratios (CR’s) from 11 to 14. Whan compared at the same Φ and CR, the reduction in fuel consumption for dissociated methanol compared to methanol (3-7 percent) was smaller than would be expected based on heating value alone. Indicated thermal efficiency with dissociated methanol was only 0.89-0.55 times that with methanol. Thermodynamic analyses were conducted to isolate the factors responsible for lower efficiency with dissociated methanol.

The conversion of solid fuels, such as coal and wood, to a gaseous fuel in an on-board gas producer was examined as a means of fueling vital transportation vehicles in case of a catastrophic shortage of crude oil. The literature on automotive gas producers was reviewed, and a preliminary design of a gas producer was formulated for a compact car fueled with bituminous coal. The influence of other solid fuels on system design and operation is also discussed along with the advantages and disadvantages of automotive gas producers.

Single-cylinder engine tests, an analytical engine cycle simulation, and automobile tests were employed to study the effects of supplementing gasoline with water for use in spark ignition engines. Factors examined include: the method of water addition (both water-in-gasoline emulsions and direct manifold water addition), antiknock characteristics with water addition, MBT spark requirement, indicated engine efficiency, engine cooling requirement, exhaust emissions, volumetric efficiency, lean operating limit, smoke level, exhaust temperature, and vehicle driveability. Among the negative aspects of water addition were increased hydrocarbon emissions and decreased vehicle driveability. Also, the polyoxyethylene type of emulsifier used in the water-in-gasoline emulsions, gave poor fuel stability and caused a rapid buildup of engine deposits. However on the positive side, water-gasoline fuels have higher octane ratings and decrease nitric oxide emissions.

Quick-release chokes may become an essential feature of advanced exhaust emission control systems to minimize emissions during warmup. However, quick-release chokes greatly impair warmup driveability when gasolines of conventional volatility are used. Consequently, modifications of gasoline volatility were investigated as one approach to restoring warmup driveability with quick-release chokes. Warmup driveability of two test cars equipped with quick-release chokes was measured on a chassis dynamometer at 40 and 68 F using fuels with widely different volatility characteristics. Warmup driveability was essentially restored by increasing fuel volatility in the 40-90% ASTM distillation range. Front-end volatility up to the 40% point had very little effect.