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High-speed digital recording of cylinder pressure data at the General Motors Research Laboratories is commonplace. Improvements in transducers and data acquisition techniques over the years have allowed increasing confidence to be placed in the magnitudes of these recorded data. Current techniques for determining the correct phasing of these data with respect to crank angle, however, have not kept pace. A new phasing technique is described which involves transmission of microwave energy through the spark plug hole and into the cylinder of a motored engine. At certain piston positions, symmetric about minimum volume, microwave resonances occur. These resonances are recorded on an oscilloscope screen along with the one-degree pulses generated by the crankshaft. Analysis of these recorded data yields pressure-crank angle phasing information accurate to the order of ±0.1°CA for open-chamber engines.

The efficiency of combustion and the production of pollutants in the internal combustion engine are strongly dependent on the turbulent flow field in the engine cylinder. In most engines, turbulence is almost exclusively generated during the induction stroke. A water analog was used to visualize and study this process for a simple geometry cylinder. The flow field, during the induction process, was observed to be structured and highly repeatable from cycle to cycle. The structure was comprised of two ring vortices, of concentrated vorticity, which were of the same scale as the engine cylinder. A detailed study of the characteristics of the vortex rings was carried out for the case of an axisymmetric cylinder geometry. Inviscid scaling laws were obtained from these results that describe the development and stability of the structured flow field.

The Laser Doppler Anemometer, a new instrument capable of making non-interfering gas velocity measurements, has been used to investigate the gas behavior in the cylinder of a firing engine. First of all, the necessary conditions for a real-time measurement of the gas velocity by the LDA are examined, and thereby two typical flow, squish and torch, in the cylinder of an engine with both motoring and firing have been measured. As a result, the optical technique is ascertained to be a promising one for application to research on a firing engine.

A closed-circuit television technique has been developed for the real time viewing and recording of combustion and related processes in internal combustion engines. The technique has been applied to a transparent piston, transparent head engine, and shadowgraphs of combustion chamber events have been observed and recorded. The technique is particularly suited for the study of changes in the combustion process due to variations of engine parameters such as mixture ratio, load, speed, spark timing, injection initiation, etc., since the changes can be observed and recorded at the same time that they occur. A brief and qualitative study of flame and pressure cyclic variations is reported and discussed as an example of an application for which the television technique is particularly suited.

This research demonstrates the capability of the Laser Doppler Anemometer (LDA) for making measurements inside a piston-engine cylinder. The backscatter mode of LDA operation, requiring only a single window in the cylinder, was used. An ensemble-average data-processing technique has been developed to analyze the raw velocity-crankangle data. Single-component measurements of mean velocity and rms velocity fluctuation at a single point are presented as functions of crankangle for three engine speeds. A comparison of motored and fired results is shown for one engine speed. Measurements of two components of velocity at several locations show the basic vortical nature of the flow field in this particular engine.

Gasoline delivery-filtration systems presently used in vehicles are highly effective. Nevertheless, there is a continual evolution of the system as vehicles with improved emission profiles and fuel economy are manufactured and alternate automotive combustion fuels are being adopted. Therefore, an investigation of the fundamental parameters controlling delivery of filtered fuel to the engine is important to the engineers responsible for new designs. In this paper the basic engineering factors required to understand how in-tank fuel strainers function are discussed. Guidance in choosing fabrics that ensure optimum performance for various types of liquid fuels is also provided.

Measurements taken in a special, single cylinder, direct injection stratified-charge engine are presented. The optical measurement techniques employed include continuous-wave laser Raman spectroscopy for fuel and air concentrations, pulsed laser Raman spectroscopy for density fluctuations, high-speed cinematography for flow visualization, and laser Doppler velocimetry for velocities and turbulence intensities. More conventional data on cylinder pressure, power, and emissions levels are also given. The purpose of the study is to demonstrate the types of detailed measurements that are now possible within an engine cylinder.

Passenger car engine lube oil filter advancements have been made to improve filter reliability. The design consists of a dual media laminate for greater dirt holding capacity and improved resistance to higher crankcase oil temperatures. Field testing has shown service life to be at least 15,000 miles with potential for longer service.

This paper discusses the engineering considerations involved in the proper selection of a medium or heavy duty truck frame for utility vehicles with primary emphasis on the mounting of aerial devices which include digger derricks, hoists, cranes and man lifts.

A brief description of the items to be included and reviewed when developing specifications for a body of Utility Maintenance and Construction vehicle. The paper contains the viewpoints of the user and not the manufacturer.

Sixteen gas analyzers are used to measure emissions into and out of the catalytic converters while conducting Environmental Protection Agency vehicle test procedures. A computer system controls the analyzer consoles, logs test data, and provides test results quickly. The computer logs data during testing, then on command transmits it to the GM Research Laboratories (GMR) Data Center. Data reduction is done at the GMR Data Center because it has a large computer to do the calculations and programmers to maintain the reduction programs. The test summary can be transmitted back to the test site. The system was tested extensively to verify accuracy of results. Gas analyzers were calibrated, data logging and handling were checked, and the data reduction programs were scrutinized. The system has given consistent results during its operation.

Material presented in the following text discusses design improvements made on a 20 year old engine testing facility. The designs include improved measurement techniques for fuel and air rate, spark angle, test cell equipment control, operator safety, automatic testing, data acquisition and processing. The new changes provide development personnel improved data accuracy and formatted test results in much less time.

Early in the 1970's, Oldsmobile recognized the need to construct a new accurate, reliable, and versatile emission test facility to accommodate the more stringent Federal and State emission standards. This paper reviews in detail: layout of the test facility, its measurement capabilities, computer data handling, storage and retrieval processes, and a special data reduction program capable of producing two or three dimensional plots of dynamic engine emission parameters. The final section reviews the facility's physical design, data acquisition capability, and computer versatility which will permit updating in the future to accommodate changes in this very fast moving field of emission measurement technology.

Boating Industry Associations (BIA) TC-W certified two-cycle engine oils are used in a variety of both air- and water-cooled engines. Some high performance two-cycle engines used in the motorcycle and snow-mobile market have shown performance deficiencies with current TC-W quality lubricants. This paper traces the development of an additive capable of meeting the demands of severe air-cooled engine tests as well as the current TC-W lubricant specification for water-cooled engines. Tests developed to evaluate lubricant performance in both air- and water-cooled engines are described. The need for standardized test procedures in addition to the BIA TC-W specification is shown.

Today's two-cycle engine oils are not expected to adequately meet future engine oil requirements. It is recommended that oil developers use a Comprehensive Oil Development Plan for future oils. A Plan should include five key elements: Engine Manufacturer Contact, Mechanism Studies and Failures Analysis, Oil Formulating, Laboratory Engine Evaluation, and Field Evaluation. These elements are described through examples of lubrication and deposit programs. The most important future oil performance requirement is considered to be scuffing control. Data from the G15 laboratory engine scuff test are presented which should assist in the development of future oils. The importance of Mechanism Studies and Failure Analysis programs to support formulation for antiscuffing is stressed. A review of published air-cooled engine deposit test procedures has shown the lack of world-wide standardization.

Development of 2-stroke cycle gasoline engines towards higher specific outputs and environmental aspects have resulted in more stringent lubricating oil requirements. A classification system is being generated by SAE/ASTM/API in cooperation with CEC to facilitate selection of suitable oils with different performance levels depending on their application. Standardized CEC Test Methods and European in-house tests used for 2stroke oil development are described and discussed. Special oils for use at lean fuel : oil ratios and biodegradeable lubricants have been developed. Typical bench and field test results obtained with modern formulation concepts and reference oils are presented.

Problems associated with use of oils for small air-cooled two-cycle engines are mainly piston deposits, ring sticking, spark plug fouling, combustion-chamber deposits, piston seizure, exhaust system blocking and visible smoke. This paper describes some test methods for evaluation of lubricants for Japanese small air-cooled two-cycle engines. Results obtained from some of these test are also expressed. The effect of base oil composition and additive type on lubricant performance is also described.

In April 1978 the Office of Road Safety conducted a press and radio publicity campaign aimed at increasing the fitting and use, by children, of conventional belts where child-restraints are not available and relocating children, particularly those unrestrained, from front to rear seats. Undertaken in States with and without child restraint legislation, the publicity campaign was evaluated using data from roadside observations of restraint fitting and use. The campaign was not effective in achieving the desired behavioural changes. However, the results provided valuable data on the carriage of children in cars and highlighted the differences between States with or without child restraint legislation.

A series of 16 sled impact tests was conducted at the Highway Safety Research Institute sled facility to evaluate the effectiveness of restraint devices and systems currently being used to transport school-bus and wheelchair-seated handicapped children. A sled impact pulse of 20 m.p.h. and 16 G's was used for all tests. Eight tests involved wheelchairs in forward-facing and side-facing orientations for head-on and 33-degree oblique impacts. Another eight tests involved forward-facing bus seats for head-on and 33-degree oblique impacts. The results generally point out the ineffectiveness of many currently used devices and systems for protecting the child in a bus collision. In six of the eight bus seat tests the dummy's head struck the back of the bus seat in front. This was primarily because of a lack of upper-torso restraint.

Child restraint performance in frontal and lateral crash simulations is presented and discussed based upon tests conducted on the Calspan HYGE acceleration sled. Differing acceleration pulses for frontal tests were used to evaluate the pulse shape effect upon the child restraint systems. Two types of three year old size anthropometric test devices (ATDs) were used and restraint systems were intentionally improperly installed in an effort to ascertain the potential hazard to the child occupant from improper installation. Data obtained include head excursion, head and chest triaxial accelerations, Head Severity Index (HSI) and Chest Severity Index (CSI) values for the ATDs. High speed movie coverage produced dummy kinematic results.