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New OSHA requirements regarding the use of VCM (vinyl chloride monomer) have been found to present specific problems with certain sampling methods and analytical procedures. This report will attempt to define some of these problem areas.

Two recently developed sheet products offer material cost savings opportunities of approximately $2.50 per typical car with catalytic conversion system. Galvalume sheet steel, an aluminum-zinc alloy coated sheet, has been used successfully for grass shields replacing type 1 aluminum coated sheet at an approximate savings of 25¢/lb. Chromized sheet, which has a diffused layer of ferritic stainless steel on both surfaces of a special low carbon sheet, is suggested as a substitute for 400 Series Stainless Steel at a material cost benefit of approximately 15¢/lb. Exhaust inlet tubes and convertor shells of Chromized have been successfully tested.

It is recognized that stratified charge combustion in a spark ignited internal combustion engine can produce improved fuel economy. A historical summary of many significant patents and articles is given pertaining to the 3-valve form of this engine combustion principle. The present social need of reducing exhaust emissions, and the renewed goal of improving fuel economy, makes this engine form one practical approach to the “clean engine” being sought for vehicular use. It uses a rich prechamber charge to provide the proper stratification. The prechamber can vary considerably in size depending upon the goals sought and the engine application. A basic requirement is that the fuel-air equivalence ratios of the charges in the two combustion chambers are within certain limited ranges to achieve proper optimization. The ratios should be 15% rich for the prechamber and 15 to 30% lean for the main chamber at the moment of ignition.

Fantastic changes are taking place in our use of resources and in our life style. The industries that supply raw materials are being bombarded by demands. All are interrelated, and to fix one problem aggravates another. This paper discusses solutions to these problems, solutions which will require more material substitution for a given application. These solutions will require our technological society and government regulations to adjust to new systems to find an adequate resolution.

Simplified curves and equations are developed that can be used to predict the vibration level of a supporting structure from the action of the various vibration sources of a slider-crank mechanism. Using a chain saw as an example, the vibration levels from each major vibration source are presented goether with the vibration level with various isolation stiffnesses as presently used in practice. The vibration levels are reviewed to determine the design parameters necessary to meet a 0.5 “g” specification, and a novel isolation concept is presented together with actual vibration spectrums.

Due to rising under-the-hood temperatures and the trend in industry in general for longer life products, the long-term heat resistance of elastomeric materials is generating considerable interest. This paper reviews some of the compounding techniques necessary to develop the best long-term heat resistant epichlorohydrin compounds. The long-term (1000 hrs.) aging resistance of these materials will be compared to more conventional materials such as CR, NBR, CSM and EPDM compounds. Also blends such as Acrylate/Epichlorohydrin and Epichlorohydrin/Chlorobutyl will be reviewed as ways to obtain a balance of heat resistance and cost.

Butadiene-acrylonitrile copolymers have been the preferred general purpose oil and fuel resistant elastomers in automotive, aircraft and industrial product applications for over 30 years. The need for improved service performance to meet more severe and/or newly emerging service requirements has prompted a number of studies to improve the performance of these polymers. This work has led to the development of a family of new and unique polymerization bound antioxidant stabilized nitrile rubbers which have outstanding heat resistance characteristics. These new rubbers also retain their age resistance qualities after exposure to oils or fuels which can extract the protective antioxidants from conventional nitrile rubbers thereby contributing to early failure of parts in service.

The stresses arising in a vehicle structural part during the operation period could be divided into three essential components. The extreme values of these components and their distribution function may be derived. Using appropriate crack propagation functions one can define the momentary service strength of the structure and the damage-function. On the basis of the new fracture model presented, the life distribution can be interpreted unambiguously. By using certain assumptions, the deverage value and the scatter of the life can be derived. The new fracture model allows the several fracture types, like static, pure dynamic, pure fatigue, and general fractures to be treated on the same basis.

A case study describes a fatigue damage analysis of a light truck frame. The objective of the analysis is to determine whether an existing frame design can safely accept a ten percent increase in load. The analysis, completed in less than a month, incorporates an experimental stress-strain analysis, proving ground test data and experimentally determined properties of the frame material. Three common methods of damage analysis and a relatively new procedure are compared and the advantages of the new method are demonstrated.

The re-evaluation of the brake blocks part of the “S” cam foundation air brake system established new understanding of component variation and interactions on performance. Each of the significant components must be understood and controlled to obtain desired performance consistency. The simple “S” cam brake is actually a complex system of variables requiring cautious evaluation.

Seat belt use inducing systems and seat belt use counting systems were installed in fleet vehicles of the Automobile Club of Southern California. The results were: 1. Mean group seat belt use for three use inducement systems were sequencing system 77%; ignition interlock system 86%; and speed limiting interlock system 81%. 2. There was no significant change of seat belt use for any of the three inducement systems according to time of exposure. 3. There was a significant difference between previous no system seat belt use (mean 24%) and no-system seat belt after exposure to the use inducing system (mean 49%). 4. The vehicle drivers were given a questionnaire at periodic intervals, the results of which indicated higher self-reported than actual seat belt use. Also specific confusion, inconvenience and discomfort factors were identified and rated. The conclusions were: 1. use inducing systems cause a significant increase in seat belt use of fleet vehicle drivers.

IN 1973, AN EXPERIMENTAL C.O.E. class eight highway vehicle was designed and built by Kenworth Truck Company to evaluate market impact generated by a unique looking vehicle. Various design aspects as related to driver comfort and associated component development are presented. To provide separate sleeping accommodations for two people, total cab height from current production models was increased by 22 inches. This increase was also used to develop a roof contour with esthetic valve and moderate air flow characteristics to the extent possible. In addition, a brief summary of actual road testing is presented.

This paper presents equations for determining the convective heat transfer coefficients of solid and ventilated disc brakes. Analysis of data indicates that the cooling capacity of a ventilated rotor is sharply reduced at lower speeds, and most cooling is provided by the increased surface area. A general relationship derived from road test data is presented that yields the heat transfer coefficient for both disc and drum brakes of commercial vehicles.

The suitability of using unleaded gasoline in military and commercially designed equipment located at four Army installations has been evaluated over a two-year period. A total of 3007 vehicles were monitored during the evaluation for maintenance and performance problems. This paper presents information on vehicle octane number requirements and octane number increase trends measured on a selected group of vehicles during the evaluation period. Details of the fuels used, vehicles tested, test procedure and results are discussed.

Lower temperatures at the sliding interface of a disc brake will reduce thermal wear and fade tendencies of friction materials. One method for achieving these lower temperatures is to improve the thermal design of gray cast iron discs. The purpose of this investigation was to study design improvements of brake discs for trucks. To accomplish this objective, an analytical thermal model was developed. The model employed the lumped parameter approach, in which the disc was subdivided into a number of small volumes. The model specifically simulated disc temperature response during 80.5 km/h (50 mph) fade tests performed on a dynamometer. The thermal model was correlated with test data to verify and improve its accuracy, and then utilized to evaluate effects of geometry changes. Results showed that mass concentration in the disc faces yields lower temperatures at the friction interface through 10 successive snubs.

Because of the increasing use of rubber formulations and plastics by the automotive industry, analytical methods are continually being sought for quality control and receiving inspection. The application of the thermal analysis technique, known as thermogravimetry, to the problems of fast quality control analysis is discussed. Specific examples in the areas of relative thermal stability, analysis of additives, and compositional analysis of formulations are presented.

The application of Proton and Carbon-13 Nuclear Magnetic Resonance Spectroscopy to the analysis of selected automotive plastics is discussed. Six nmr spectra are presented and the chemical shift values assigned to structural features for each polymer. The utility of nmr analysis for the characterization of organic polymers is illustrated by the application to the identification of polycarbonate thermoplastic and a polyurethane elastomer and to the determination of stereochemical configuration of poly(methyl methacrylate).

The influence of selected engine oil, fuel, and driving schedule variables on combustion chamber deposits and octane requirement increase (ORI) has been investigated during vehicle fleet tests with late model cars. Greater octane requirement increases occurred with: (a) an engine oil containing bright stock compared to an engine oil without bright stock, (b) an unleaded fuel which contained a polymeric detergent-dispersant additive with a large amount of carrier oil, compared to other unleaded fuels with conventional additive packages, and (c) customer-type driving compared to rapid mileage accumulation on a chassis dynamometer. Octane requirement increase was not affected by: (a) lead content of the fuel; or (b) ashless engine oil compared to a conventional ash-containing oil. All of the ORI with unleaded fuel can be eliminated by removing the combustion chamber deposits, and about two-thirds of the ORI is caused by deposit accumulation in the end-gas region of the chamber.

Two successive surveys and round-robin interviews were conducted to determine if there might be in the offing for automobiles an alternative engine which would exhibit low emissions meeting the most stringent requirements. Comparison between engines were couched in terms of selected “acceptability factors” which went well beyond emissions, alone. The overall acceptability was evaluated considering emissions, customer requirements for an engine, manufacturers' requirements for an engine, and engine efficiency and fuel versatility. An attempt was made to establish a time scale as to R and D requirements and eventual production. Comparison of all engines was made with equivalent pre-control Otto cycle engines as the standard. Alternative engines were deemed to be any power plant that was not based on spark ignition Otto cycle engines, or diesel engines. The remaining heat engines largely used continuous combustion as the heat source.

In recent years, several programs have been conducted at the Ethyl Research Laboratories in Detroit, some in cooperation with a major oil company, to measure the value of lead antiknocks in fuels for European cars. These heretofore unpublished studies show: 1. A positive lead road bonus. 2. Tetramethyllead (TML) is more effective than tetraethyllead (TEL). 3. The lead road bonus increases with engine operating severity. The lead road bonus is defined in broad terms as a combination of three effects - lead-in-fuel, fuel sensitivity, and engine deposits. The engine-deposit effect is not of major significance in European cars. Much of the confusion over the value of lead antiknocks in European cars and fuels in recent years can be attributed to improper definition of the lead road bonus, at times coupled with inappropriate rating conditions and limitations in fuel design. The importance of these studies is significant in view of the trend toward smaller cars.