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The development of the AUTO TEMP II Temperature Control System used in Chrysler Corp. vehicles is summarized. A description of the design, development, function, and manufacturing aspects of the control system is presented, with emphasis on unique control parameters, reliability, serviceability, and check-out of production assemblies. Auto Temp II was developed by Chrysler in conjunction with Ranco Incorporated. The servo-controlled, closed-loop system, which has a sensitivity of 0.5 F, utilizes a water-flow control valve for temperature control, along with a cold engine lockout. The basic components are: sensor string, servo, and amplifier. All automatic functions involving control of mass flow rate, temperature, and distribution of the air entering the vehicle, are encompassed in one control unit. All components are mechanically linked through the gear train and are responsive to the amplifier through the feedback potentiometer.

The paper outlines testing, development, and operation of the first production four-wheel slip control system for passenger cars in the United States. The Chrysler Corp. calls the system “Sure-Brake,” but it is more generally known as “anti-skid.” The first portion of the paper deals with considerations that led Chrysler into the Sure-Brake system, the philosophy behind the system, and a detailed explanation of its operation. The second portion deals with the development and testing of the system, leading to its release as an option on the 1971 Imperial. The testing program introduced a new dimension to brake engineering. Before the advent of wheel slip control systems, many thousands of brake tests were conducted but were always terminated at the point of skid. These tests were also conducted mainly on black top or concrete roads. For the first time, thousands of stops were made at maximum deceleration on every available surface.

A system for controlling gasoline evaporation losses from 1970 model Chrysler Corp. cars and light trucks was developed, certified for sale in California, and put into production. Evaporation losses from both the carburetor and the fuel tank are conducted to the engine crankcase for storage while the engine is shut down. The vapors are removed from the crankcase and utilized in the combustion process during subsequent vehicle operation. Particularly interesting in this unique, no-moving parts system, are the reliability and durability, and the vapor-liquid separator “standpipe.”

The aerodynamic features of the race version of the Charger Daytona, an aerodynamically modified 1970 Charger, are discussed. Effects of major specific modifications are evaluated individually and as a total package. Wind tunnel techniques and philosophy employed in the Daytona Development Program are also discussed.

The SAE Recommended Practice J963 “Anthropomorphic Test Device for Dynamic Testing” describes a standard 50th percentile adult male anthropomorphic test dummy. For nearly three years the Crash Test Dummy Task Force worked with the limited data available in selecting values for the body dimensions and ranges of motion. The data for specifying the values of mass distribution were developed experimentally as was a test procedure for determining the dynamic spring rate of the thorax.

This paper describes techniques that predict and analyze dynamic response of vehicles traversing random rough surfaces. Road irregularities are statistically classified by frequency and amplitude distribution. This classification determines the nature of random inputs to mathematical vehicle models and allows computer prediction of dynamic response of a simulated vehicle. Once inputs and models are defined, parametric analysis with output criteria specified statistically can be performed. This allows prediction of vehicle riding quality and evaluation of design concepts. Statistical analysis of accelerometer measurements on actual vehicles permits verification of the design process and meaningful comparison between vehicles.

The heater air flow rate is a function not only of the heater itself but also of the size and location of the heater system air inlets, the car body air outlets, and the body surface pressure at these inlets and outlets. Favorable pressure conditions generally exist at the typical top cowl heater air inlet; however, the aerodynamics of each particular vehicle should be studied to confirm the existence of these conditions. Little consideration has been given to body air outlet pressure conditions since body leakage paths have generally served as adequate air outlets; but, as body leakage is reduced, specific air outlets must be considered and a knowledge of aerodynamics is essential to the achieving of appropriately sized and appropriately located air outlets.

The authors summarize information on effects of tires on tandem truck ride and vibration problems. An appraisal of research and a request to face the challenge of acquiring better engineering measurements of vehicle vibration are given.

This paper discusses the development of criteria necessary to establish reliable lunar exploration and construction vehicle concepts. To establish the basis for the development of these criteria, an exploration mission using the presently conceived Apollo launch vehicle system is described. The criteria resulting from the study of the contribution made by the hostile lunar environment and the life support system requirements within the framework of the selected mission are established. Soils testing in a hard vacuum is described, as are tests of models under simulated lunar terrain environment. Two lunar vehicle configurations are reviewed, including design parameters and subsystem development.

THE GRADEABILITY formula can be used as the basic means for rating a truck transmission. By correlating the gradeabilities in the various gear ratios with a highway requirement probability curve, the per cent of time in each ratio can be obtained. The required hours of gear life for each ratio are then determined, and compared with the available gear life in the ratios. This procedure gives a detailed analysis of a transmission rating for one vehicle specification at a specified mileage between overhauls. A limitation of the system is that it cannot be applied quickly to various vehicle specifications. The paper outlines the method for constructing a nomogram to overcome this.*

THIS year the Chrysler Corp. has introduced a new V-8 engine designed to meet market conditions requiring larger displacements. Versions of the basic engine are available in several models of the Corporation's cars. This engine provides increased vehicle performance with excellent economy, durability, and quietness. Emphasis on minimum weight and production economy led to many novel design features which should interest the automotive engineer. The paper will include a review of the overall design considerations, as well as a description and discussion of the engine and its component parts.

THIS paper outlines tests made to verify the SAE recommended practice for estimating truck ability performance described in TR-82. The author has collected data on four vehicles and compares it with the results computed in TR-82 and with a Method X. The data includes information on air and rolling resistance, effect of wind velocity, chassis friction power, grade ability, and the like. The author concludes that the SAE method of TR-82 is at the present time the most reliable method for computing truck ability.

IN 1951 Chrysler Corp. began working on a new torsion suspension. In this paper the authors describe details of the development and design of the suspension, now available on 1957 cars. The authors claim the Torsion-Aire suspension has the following advantages: reduced highspeed float, boulevard harshness, impact harshness, road noise, body roll, nose dive, and acceleration squat; better directional stability and cornering ability; fewer lubrication points; and a better balanced ride. The main feature of the front suspension is the use of torsion bars. One of the principal advantages of torsion bars is their weight: 10 lb as compared to 15.8 lb for a 1956 production coil spring.

AS a basis for the analyses of this symposium, a hypothetical car has been used to evaluate the engine power distribution in performance. Effects of fuel,-engine accessories, and certain car accessories are evaluated. The role of the transmission in making engine power useful at normal car speeds is also discussed. Variables encountered in wind and rolling resistance determinations are reevaluated by improved test techniques. Net horsepower of the car in terms of acceleration, passing ability and grade capability are also summarized.

WORK done in a development program relative to camshafts and tappets in the design of the Chrysler overhead-valve V-8 engine is described. The types of failure encountered are categorized as wear, scuffing, and fatigue. An accelerated test procedure was designed to promote early cam-tappet failures, and the development work was predicated upon the results obtained therefrom. Among the variables affecting the failure conditions, major emphasis was placed on material development. Specifically, the greater amount of time was spent in determining the optimum tappet material, while some time was devoted to the camshaft material. A combination of adjusted chemical composition and heat-treatment of hardenable cast iron for camshaft and tappets provided the best solution to the failure problems.

A SIMPLE method of predicting truck performance in terms of grade ability at a given road speed, taking into consideration rolling resistance, air resistance, and chassis friction is presented here. A brief review of fundamental considerations is given first, then the method recommended for predicting vehicle ability at a selected speed, and finally a few words on the prediction of maximum possible road speed and selection of gear ratios. The basis of the solution is the determination and expression of vehicle resistances in terms of horsepower - that is, in terms of forces acting at a velocity. A convenient method of solving the grade problem at a given speed is by means of a tabular computation sheet, which is given, together with tables and charts. These assist in making the computation an easy one as well as giving the necessary data on vehicle resistances.

THE Junkers 211B engine follows the usual German practice of very large displacements and conservative mean effective pressures and rotative speeds. However, the relative light weight per unit of displacement results in a net weight per horsepower that is not far above its competitors. Fully automatic devices which control propeller speed, manifold pressure, mixture ratio, spark advance, and supercharger gear ratio follow the German policy of removing all possible distractions from the pilot. This is one of three large liquid-cooled engines known to be produced in quantity in Germany; it powers an impressive percentage of the Luftwaffe. While of external appearance and displacement that resemble the Daimler-Benz DB-601 engine, the fundamental construction, detail design practice, and metallurgy of the Junkers 211B are surprisingly different.