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During development of the General Motors rotary engine, the lubricant was recognized as important to its success because certain lubricants produced deposits which tended to stick both side and apex seals. Consequently, it was decided to develop a rotary engine-dynamometer test, using a Mazda engine, which could be used for lubricant evaluation. In an investigation using an SE engine oil with which there was rotary engine experience, engine operating variables and engine modifications were studied until the greatest amount of deposits were obtained in 100 h of testing. The most significant engine modifications were: omission of inner side seals, plugging of half the rotor bearing holes, pinning of oil seals, grinding of end and intermediate housings, and using a separate oil reservoir for the metering pump. Using this 100 h test procedure, three engine oils and five automatic transmission fluids were evaluated.

Most transducers offered commercially are suitable for laboratory, aerospace, or industrial process applications but do not meet additional, stringent automotive requirements. A need exists, both present and future, for various types of transducers in automotive powerplant control systems. Possible electronic systems and subsystems requiring transducers are discussed, and the types of transducers needed for these systems are described along with a discussion of a general set of specifications with respect to accuracy, reliability, and durability. Substantial transducer development is needed to enhance the advancement of certain automotive electronic systems. This paper points out these requirements to the electronics industry in an effort to encourage a mutual industry development that will advance the technology.

Engine oil test Sequences IIA and IIIA have been developed to replace Sequences I, II, and III. These new sequences are designed to evaluate lubricants for use in current passenger car engines under severe (MS) service conditions. Lubricant performance is evaluated with respect to scuffing wear, rust, corrosion, deposits, and rumble. The Sequence IIA and IIIA test procedure involves major changes which affect the evaluation of engine rusting and provides improved correlation between test results and short-trip service. Average engine rust ratings correlate with service data within ±0.5 numbers. The new test also provides better repeatability and reproducibility in a significantly shorter schedule. The rust repeatability and reproducibility is less than ±0.2 and ±0.6 numbers, respectively. Test time has been reduced 52%.

Controlled-slip differentials (CSD) improve car operation under wheel slipping conditions. The performance of CSD's is dependent upon two criteria associated with clutch friction: “chatter” and “effectiveness.” “Chatter” is an undesirable noise which may occur during differential action. “Effectiveness” is a measure of the ability of the CSD clutches to transfer torque, during wheel slippage, to the wheel with the greater traction. The objective of this investigation was to definitely establish the cause of chatter, measure CSD effectiveness, and relate friction characteristics of lubricants to CSD operation. In tests with an instrumented car, it was found that both chatter and effectiveness are strongly influenced by the lubricant. Chatter occurred with lubricants that produced an increase in clutch friction with decreasing sliding speed. Chatter did not occur with lubricants containing friction modifiers which produced a decrease in clutch friction with decreasing sliding speed.

As part of General Motors effort to improve fuel economy, the effects of engine and power train lubricant viscosities were investigated in passenger car tests using either high- or low- viscosity lubricants in the engine, automatic transmission, and rear axle. Fuel economy was determined in both constant speed and various driving cycle tests with the car fully warmed-up. In addition, fuel economy was determined in cold-start driving cycle tests. Using low-viscosity lubricants instead of high-viscosity lubricants improved warmed-up fuel economy by as much as 5%, depending upon the differences in lubricant viscosity and type of driving. Cold-start fuel economy with low-viscosity lubricants was 5% greater than that with high-viscosity lubricants. With such improvements, it is concluded that significant customer fuel economy gains can be obtained by using the lowest viscosity engine and power train lubricants recommended for service.

A viscoelastic neck structure that responds to impact environments in a manner similar to the human neck is described. The neck structure consists of four ball-jointed segments and one pin-connected “nodding” segment with viscoelastic resistive elements inserted between segments that provide bending resistance as well as the required energy dissipation. Primary emphasis was placed on developing appropriate flexion and extension responses with secondary emphasis placed on axial, lateral, and rotational characteristics. The methods used to design the resistance elements for the neck structure are discussed. Three variations of the resistive elements have been developed that meet the response characteristics based on the data of Mertz and Patrick. However, no single resistive element has satisfied the flexion and extension characteristics simultaneously, but such an element appears to be feasible.

This paper summarizes an analysis, design, and test project in which a dummy chest structure was developed. The chest consisted of mechanical elements that had been characterized by computer simulations as giving responses to blunt frontal impacts necessary for biofidelity. An analysis of mechanical rib structures indicated that materials having a high ratio of yield stress to modulus of elasticity were required. Only metals having unusually high yield strengths, such as spring steels, qualified. A mechanical system was developed with steel ribs pivoted at each end as a primary spring. A secondary spring was a pair of commercially available die springs acting in parallel with the ribs after 25.4 mm (1.00 in) deflection. A fluid damper was developed to provide the damping. The chest structure was tested under conditions modified from those used by Kroell. The modifications were holding the spine rigidly and reducing the impact masses.

Future low emissions engines will burn unleaded gasoline. Compared with engines of 1970, future engines will have lower concentrations of NOx in the blowby gases, and lower blowby flow-rates; however, oil temperatures will probably be unchanged. The consequences of these conditions for engines using high quality (SE) oils at current drain intervals are: virtual elimination of rust, reduction of sludge, no effect on wear and oil thickening, and possible worsening of varnish. Therefore, extension of the drain interval with SE engine oils in the future may be possible, but final decisions will depend on the findings of research in the areas of engine wear and varnish, and oil thickening.

Two Highway Safety Research Institute (HSRI) dummies were tested and evaluated. Based on the analysis given, the HSI dummy should not be used for vehicle qualification testing. However, many of its components offer viable alternatives for future dummy development. The dummy was found to have inadequate biomechanical fidelity in the head, neck, and chest, although its characteristics were very promising and, as a whole, biomechanically superior to the Hybrid II. Its repeatability and reproducibility in dynamic component tests were better than the Hybrid II dummy. In particular, the HSRI friction joints were outstanding in repeatability and had a significant advantage in usability in that they do not require resetting between tests. In three-point harness and ACRS systems tests, the values of injury criteria produced by the HSRI dummy were generally lower than those obtained with the Hybrid II, especially the femur loads in the ACRS tests.

A five-vehicle, 64 000-km test with 7.45 litre V-8 engines was conducted to determine if synthetic engine oils provided performance sufficiently superior to that of conventional engine oils to permit longer oil change intervals. The results show better performance in two areas of deposit control; inferior performance with respect to wear protection; and essentially equivalent performance in the areas of fuel and oil economies. Based on these data, it was concluded that synthetic engine oils do not provide the necessary performance required to safely recommend their use for extended oil change intervals. In addition, a cost analysis shows that the use of synthetic engine oils, even at a change interval of 32 000 km, will essentially double the customers' cost compared with conventional engine oils at GM's current 12 000-km change interval.