Search Results

Tests of laser ignition are conducted in a combustion bomb. A range of fuels is investigated comprising isooctane, cyclohexane, n-heptane, n-hexane, clear indolene, and No. 1 diesel fuel. The ignition characteristics of laser-induced sparks are compared with sparks generated with a spark plug for different air/fuel ratios. The power density required to produce laser induced sparks is investigated. Although laser ignition appears to be impractical as an ignition device because of its low efficiency and high cost, it presents some interesting possibilities compared to the standard spark plug in that the laser spark is electrodeless and can be positioned anywhere inside the combustion chamber. Its primary use appears to be as a research tool.

Increased demand for reduced electromagnetic radiation from small engine operation has necessitated an evaluation of the effectiveness of various suppression methods available to the engine manufacturer or end-user. This investigation studied the effectiveness of different suppressors in spark plugs, spark plug boots, shielded connectors, and ignition leads. Suppression from resistance, inductive resistance, and shielding were evaluated. This work was undertaken on “breadboarded” ignition systems of the battery coil inductive, magneto, and capacitor discharge types. Results from these were then compared to actual spark ignited engines mounted in lawnmowers, snowmobiles, chain saws, and a motorcycle.

In the first year of the nonmandatory phase of New Jersey's idle inspection/maintenance program, over 3 million vehicles were tested in the state's 39 inspection stations. This paper investigates some equipment, procedural, and vehicle-oriented variables that can occur in an on-line system. The relationship of garage types of analyzers to the inspection network is also presented. The inspection equipment is described, and an assessment of its performance with design specifications is made. Operational procedures and manpower constraints are also described with relevancy to mass-production, quality-control applications. A recent proliferation of low-cost, garage-type, infrared exhaust equipment has made it necessary to evaluate and correlate such equipment to the inspection equipment. Special design features are presented, and a comparison of these features is discussed for those analyzers approved by the state of New Jersey.

Data from two test fleets, representative of the U.S. car population, were used to evaluate the relative merits of procedures using idle and short loaded emissions tests to reduce vehicle exhaust emissions. The incidence of engine malfunctions and the effect of each on idle emissions were determined. From this, a diagnostic procedure based on non-loaded testing (idle and 2500 RPM emissions) was developed. Tune-up repairs beyond those indicated by the procedure produced no significant further emissions reduction. The data show that non-loaded emissions testing combined with the non-loaded test diagnostic procedure can be as effective as loaded testing combined with a loaded test diagnostic procedure in reducing emissions both at idle and under load. The study also showed that the non-loaded test diagnostic procedure more correctly identified the malfunctions responsible for cars failing the emissions tests than did the loaded test procedure.

The effects of API SE engine oils on the activity of a 1975 prototype monolithic, noble metal oxidation catalyst have been studied in long-term multicylinder laboratory engine tests. Results of this work showed that oil consumption rates, up to 1 qt/1000 miles, and lube ash up to 1.6%, do not significantly affect catalyst activity in 500 hour tests, equivalent to 20,000 miles (32,180 km). A commercial type 1% ash SE oil showed only a small effect on catalyst activity in an extended 1250 hour test, equivalent to 50,000 miles (80,450 km). At the end of the test, the catalyst met the original 1975 emissions standards of 3.4 g/mile CO and 0.41 g/mile HC. A higher-than-normal phosphorus-containing oil (0.32% P) caused significant loss in catalyst activity after testing for 30,000 miles (48,270 km). This suggests that any need for increased phosphorus-containing additives in future oils could cause catalyst poisoning before 50,000 miles.

Certain sections of Motor Vehicle Safety Standard 121 require that air braked commercial vehicles have the capacity to produce an average deceleration of more than 17 feet/sec2 from 60 mph to stop without prolonged wheel lockup on a surface characterized by an ASTM skid number of 75. Since commercial vehicles commonly include a wide variety of geometric and load configurations, careful steps must be taken by the manufacturer to assure conformance of each vehicle produced. Ford Motor Co. has found it useful to approach this problem with a program combining vehicle testing and computer simulation. A simple computer model is employed to select critical vehicles for subsequent testing. These vehicles serve a twofold purpose; to demonstrate empirically conformance to the stopping distance requirements of MVSS 121, and to permit correlation of a more sophisticated simulation. This more comprehensive model is then utilized to calculate the longitudinal braking performance of other vehicles.

A short-trip rust test was conducted on both ash-containing and ashless oils, using both leaded and nonleaded fuels. Our findings show that ash-containing formulations are greatly superior, particularly during the last phase of this test. When one of the ashless formulations was used with nonleaded gasoline, a 3 average lifter rust number improvement was obtained over that found in leaded gasoline. Pushrods and oil pump relief valves, in general, rusted very little, which is contrary to rusting found in Sequence Test IIC. Ash-containing oils allowed spotted patches of rust on the nontraveled areas of the hydraulic lifter plunger while ashless oils allowed an even rust on the total area of the traveled part. New lifters installed at the intermediate inspections had accumulated as much rust by the final inspection as those present from the beginning.

Lengthening the engine oil-change interval would reduce the frequency of automotive maintenance, reduce the amount of oil required to service the car population, and reduce the potential pollution problem resulting from the disposal of the used oil. Tests were run using 1967-1972 model U.S. passenger cars, operating in several types of service. Using unleaded instead of leaded gasoline reduced deposits and wear. With unleaded gasoline, doubling the oil-change interval had no significant effect on deposits and wear, but did increase oil filter plugging frequency. Deposits and wear were less with unleaded gasoline and doubled oil-change interval than with leaded gasoline and “standard” oil-change interval. Doubling the concentration of additives used in current quality oils was more effective at reducing deposits and wear than was doubling the engine crankcase ventilation rate.

The brake fluid temperatures of three passenger cars were monitored during Alpine vehicle trials in Italy and Switzerland. Comparison of the data obtained with those from similar evaluations in the United States shows that European conditions can make greater high-temperature demands on brake fluid, temperatures above 150?C being frequently experienced. The high-temperature performance requirements of European brake fluids are discussed.

This paper presents preliminary results of studies of the feasibility of applying electro-optical diagnostic techniques to diesel engine research. A 2-cycle, 3-cyl, diesel engine was modified by installing quartz windows in the combustion chamber to provide optical access. Techniques investigated include photography, holography, laser resonance absorption spectroscopy, and laser velocimetry. Droplet formation, breakup, and combustion can be observed in the combustion chamber in three dimensions using holography. The same hologram can be used for particle sizing and flow visualization studies. Formation of certain hydrocarbons can be observed in real time with resonance absorption, using a tunable He-Ne laser. It has been established that laser velocimetry can give components of air velocity in the combustion chamber of a motored diesel engine.

Silicone based brake fluids have demonstrated performance characteristics that are improvements over current brake fluids. They do not absorb water through elastomeric brake hoses, and their boiling point and low temperature viscosity do not change in service. The tendency toward brake system corrosion and the vapor pressure of silicone brake fluids are minimal. Silicone brake fluids are compatible with brake system components and will function as an effective brake fluid even when mixed with glycol brake fluids.

The primary function of a motor vehicle brake fluid is to provide a means for transmitting pressure from the brake pedal to the wheel cylinder or caliper where the pressure is transformed into the required braking effort. In order to perform this function efficiently, the brake fluid must remain in a liquid state free of gas or air bubbles so that compressibility is not a significant factor. The performance of brake fluid in braking systems in service is a matter of primary interest to brake engineers. The effect of water contamination on conventional glycol ether type brake fluids is discussed and compared with the capabilities of water intolerant fluids in conventional braking systems.

For several years a search has been conducted for improved motor vehicle brake fluids not regulated by present SAE or federal specifications. Safety performance needs are exceeding the present capability of conventional brake fluids, and federal improvement of performance specifications is currently under way to remedy this situation. Silicone-based brake fluids have been the only viable product developed to date. The primary goal of this search has been based on the need to identify a fluid that can be used in any vehicle on the road with no detrimental effects on any component of the braking system. This paper discusses silicone hydraulic brake fluid formulations that are capable of performing this first and most important task. Physical properties of silicone fluids that provide improved safety and performance are presented.

Extensive toxicological studies of polydimethylsiloxanes, popularly referred to as “silicones,” have shown that these materials rank among the least hazardous of all industrial materials. Nonetheless, adoption of silicone brake fluids by only a portion of the automobile industry could result in appreciable environmental imposition, thus posing a potential ecological problem. Considerations such as toxicology, biodegradability, disposal or reuse, and effects on manufacturing personnel and processes are as important as the more visible performance parameters, and must be resolved satisfactorily. These topics are the subject of this paper.

A series of experimental programs was conducted to provide an empirical data base for a computer model of the economic effectiveness of mandatory inspection and maintenance of light-duty vehicles. The experimental programs provided four basic data sets: 1. The frequency and extent of engine maladjustments and component failures of in-use vehicles. 2. The change in exhaust emission levels that results from changes in engine adjustments and component condition. 3. The deterioration of engine adjustments and components and the associated deterioration in exhaust emissions with the accumulation of time and mileage. 4. The ability of automotive service organizations to detect and repair engine maladjustments and failures. The data that resulted from these experiments were effectively employed in the computer model.

A program of vehicle inspection and maintenance has emerged as potential strategy for reducing harmful exhaust emissions from automobiles. Of the several short-term approaches now available for controlling vehicular emissions, an inspection program has the capacity for affecting the largest number of vehicles within the population. The purpose of this study is to attempt to characterize the economic effectiveness of a mandatory inspection maintenance program. Results from this analysis will show that under proper conditions an inspection program can serve as a viable component of an emission control strategy.

Since the autumn of 1967, we have been developing ignition systems using opto-electronic bistable triggers which accurately sense engine position at any speed and produce a constant crank angle dwell function in the same way as would a perfect set of cam-operated contacts. To date, over 10,000 of these systems are in use, and many have exceeded 150,000 miles of operation with only spark plug maintenance. This paper explains our preference for the bistable opto-electronic trigger and our reasons for choosing the engineering paths we have taken.

The function of the position transducer in electronic ignition control is discussed and a desired performance evolved. The transducer characteristics which influence aspects of the performance, and the imposed environmental conditions, both mechanical and electrical, are considered and a specification is proposed. A number of transducer systems at present in use are examined in detail against this specification, and the main features of some alternative types are reviewed.

This paper describes two instruments for electronically controlling ignition timing that were developed for the investigation of ignition timing control surfaces. The first instrument described generates straight-line advance curves with breakpoints as a function of manifold pressure and engine speed. The second instrument described is more versatile and allows the generation of advance curves that are a general function of two independent variables, one of these being engine speed. Use of the equipment to provide specifications for the design of mechanical distributors and also for the design of more sophisticated types of electronic advance systems is described, and some results are given.

For 1974, Ford Motor Company is providing, as standard equipment, a solid state ignition system on all 400 CID and 460 CID engines as well as on all California vehicles equipped with 200 through 351 CID engines. This paper explains the Ford solid state ignition system and the objectives and design philosophy that was used in the development of the system. Further, a review of the design and production validation test plans is discussed. With this background, specific examples of the effectiveness of complete problem analysis for fundamental cause and corrective action is presented in addition to control methods and evaluation of corrective action. This problem analysis system allowed this automotive electronic product to go into production with a high degree of confidence in meeting the reliability goals.