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Development of emission control systems for a complete line of heavy-truck gasoline engines is presented in this paper. Experience gained in emission control programs for engines used in light-duty vehicles proved beneficial in establishing basic guidelines for heavy-truck program. Various engine modifications, primarily concerned with induction systems and combustion chambers, provided sufficient emission reduction to meet 1969 California and 1970 Federal standards. Secondary air injection into exhaust was not required. Durability tests required for certification indicated the necessity of adhering to recommended service procedures to maintain low emission levels.

A summary of the effects of Public Law 89–563 -- The National Traffic and Motor Vehicle Act -- on the Truck Body and Equipment Industry in relationship to the manufacturer and/or distribution of “multistage” manufactured vehicles.

Modern turbocharged diesel engines employ exhaust driven turboblowers operating at high speeds up to 100,000 rpm. The performance assessment of such units demands precise and controllable power absorption and torque measurements at these very high rotational speeds. Additionally the parameters, speed, mass flow, static and dynamic pressures and temperatures must be measured. The turbine power absorption and torque measutement present unique problems. The remaining parameters may present some difficulties but generally the problems are not so great. The design of a high speed dynamometer and the development problems encountered are described. The dynamometer has been used to establihs the performance characteristics of a C. A. V. 01 turbocharger and these are reported.

In general, noise within an antifriction bearing can be classified as coming from random and periodic sources. The most annoying and preventable come from periodic causes, for example, a nick on a bearing raceway due to handling damage during assembly. As an aid in detecting such periodic sources in a tapered roller bearing, formulas are provided which determine the rate of contact for a specific point on one of the raceway surfaces, that is, cup, cone, or roller. Some experimental evidence demonstrating the worth of such an approach is included.

This paper reports the results of a series of vapor lock road tests on 26 cars (1966 models), half of which were equipped with exhaust emission control systems. The objectives of the tests were to determine the effect of emission controls on vapor locking tendencies, to study effects of fuel volatility and operating conditions on fuel system temperatures, and to study correlation of these temperatures with temperature versus vapor/liquid ratio characteristics of fuels. The data obtained show no significant difference in vapor locking tendency between the emission control equipped and nonequipped cars as groups, though significant differences are shown for some individual car pairs. An analysis is presented of the relation between fuel volatility, pump temperature during acceleration, and the onset of vapor lock.

The tendency of motor gasolines to form deposits on the intake valve and port surfaces of spark-ignition engines can be evaluated by a bench apparatus developed for the U.S. Army. The apparatus consists of a carbureted fuel-air system which sprays the test fluid on a heated deposit collecting tube at a 2.0 ml/minute rate. Combat gasoline (MIL-G-3056C), commercial (or VV-G-76) gasolines, and special solvents can be evaluated, using a sample volume of 150 ml. The results obtained by this technique have been correlated with data obtained during a military vehicle fleet test. The procedure has also been used to study effects of gasoline additives, storage conditions, and storage duration on fuel degradation, and as an aid in the development of deterioration predictive tests. The results of a round-robin tests for reproducibility initiated at Army petroleum testing laboratories within the United States, are provided.

This paper presents unpublished data on physical properties and bond strength of heavy duty piston ring facing materials including the presently used chromium and molybdenum. Data on the new RC-1, RC-2, chrome carbide moly, and the new “moly-over” facings are provided, and low friction coatings are discussed. Engine test results on scuff and abrasive wear and performance in high bmep diesel engines are reported.

Ten series of fractional factorial tests for oil consumption on nine small bore, high speed diesel engines have revealed favorable factors for top, intermediate, and oil rings, pistons, and liners that may be used in the initial design of a diesel engine. Blowby is much less affected by these factors, and so the factors may be chosen for oil control with but little penalty to blowby control. An enormous amount of additional work is necessary to refine further the parameters tested and to investigate new parameters.

Small engines may require soundproofing to eliminate one or more of the following effects: hearing loss, speech interference, community annoyance, detectability, and psychological disorientation. Detectability criteria are frequently associated with military applications and may require the use of a soundproof enclosure in addition to other engine treatments. Acoustical noise sources are conveniently classed as either aerodynamic or mechanical. Aerodynamic sources are predominant on small engines. Treatment of exhaust noise by individual components, e.g., muffler, is inadequate; a system approach, through the use of an electro-acoustic analog computer, has proved to be a much more satisfactory procedure.

This paper outlines the procedure used at Perfect Circle to determine coating application parameters, to evaluate coating quality, and to evaluate coating performance for new piston ring coatings. It includes descriptions of bench tests, procedures for measurement of physical properties, and descriptions of test techniques The paper outlines a sound engineering approach to developing and evaluating wear coatings for piston rings which can be extended to other coating applications.

Combustion engines with up to 48 cyl have been built. It is shown that this is neither accident nor fanciness when high specific power output is involved. As is demonstrated on hand of equations, the subdivision of a certain displacement into larger numbers of smaller cylinders brings about a substantial increase in power. At this time, for example, more than twice that of single cylinder engines. Values of highly developed motorcycle competition engines are compared with these theoretical results and an amazingly high degree of agreement exists. These laws are not limited to motorcycle engines, but may be used for other applications also.

The constant demand by engine builders for increased brake mean effective pressure (bmep) has made piston and ring temperature a serious limiting feature of engine development. The various methods previously employed to cool the piston are contrasted with the new approach of coring the oil-cooling passages by means of a water-soluble core. The development by Wellworthy of three practical foundry techniques embodying this principle which also permits the use of armored top grooves is described, with typical examples of such pistons. The effects of cooling in terms of piston temperature distribution are shown. The technique so far covers pistons 3 to 10 in. in diameter, and is fully patented.

This paper describes a cylinder plateau bore finish derived from a production process. The resulting surface is clean and free from ragged honing lines. Consistency in production is achieved as a result of the nonsensitivity of the process. Details of honing sticks, production process, control capability, and engine test results are discussed. Bore areas have been analyzed by viewing “Stereoscan” shots of the honed surface.

A new 2-ring piston package has been developed which has proven successful in internal combustion engines. The need for a compact piston arrangement is discussed along with the steps followed to arrive at excellent oil economy. The paper presents other advantages related to cost savings, lower wear, and reduced engine friction. The paper discusses applications of the compact piston package along with its advantages in designing compact engines.

This paper describes the importance of design, fabrication, and management procedures in reaching the objectives of low cost launch vehicles. Principles and philosophies essential to low cost launch vehicles are discussed and supported with examples of proven practices in somewhat parallel fields of endeavor. Progress is reported on the technology phase of the Air Force's low cost propulsion development program. The presentation concentrates on the development of pressure-fed, liquid propellant rocket propulsion for meeting the program objectives. Most of the management aspects discussed relate to the fundamentals that are essential in meeting cost goals.

Helicopter design trends towards increased blade loadings and higher tip speeds have resulted in generation of higher levels of rotor noise. This paper describes experimental programs to establish operating limits which, if observed, will result in rotary-wing aircraft with subjectively acceptable acoustical signatures.

This paper discusses fabrication results experienced with HY-140 steel flight type pressure vessels. HY-140 steel is a recently developed quenched and tempered alloy (5Ni-CR-Mo-V) structural steel with a yield strength of 140,000 psi. Fabrication techniques applied, the tooling used, and the problems encountered are described in detail.

In recent years, several innovations have been made in wind tunnel testing techniques which have significantly improved the testing cost effectiveness. Use of colored water spray in low speed testing causes unsuspected vortices to stand out allowing quick and accurate drag reduction filleting to be prepared. Simultaneous force and pressure model transonic testing has reduced the time and cost to arrive at a low drag airplane configuration by more than 50%. Means are being developed to accurately predict high Reynolds number transonic airloads from low Reynolds number data. The use of accurately sized glass beads to provide boundary layer transition for transonic testing has been found to reduce run-to-run drag data scatter by more than 50%.

This paper discusses the impact of airline transportation on the business and leisure worlds, the demand for greater effectiveness in servicing larger numbers of passengers each year, and the need for more stringent public health measures in the preparation, storage and service of foods. Technical advancements, particularly in low temperature storage as a solution toward meeting the high and low temperature requirements of the U. S. Public Health Service and Western Air Lines operating experience with cryogenic cooling of galleys on their 707, 727, and 737 fleets are reviewed.

The new generation of large transport aircraft require the utilization of improved development test techniques discussed in this paper to ensure timely and efficient development cycles. Although the development test program on the C-5, largest of today's airplanes, has not been completed, a comprehensive accumulation of significant data in all test phases and extensive experience in managing and conducting the testing of these huge transports have been obtained. The C-5 greatly advances the state-of-the-art, but more important to this presentation are the advancements in test techniques. Increased aircraft size and complexity require additional emphasis on early, valid planning for test facilities and support equipment. Improved techniques for data retrieval and additional sophistication in laboratory test loading systems are essential for efficient accomplishment of the program.