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Economy tests carried out in France indicate that it is possible to obtain a larger number of miles per gallon from cars made there than from cars made in this Country. The author states that it would be well to make a careful study of the factors influencing car economy and to assure that our future car models take full advantage of all possible means of increasing their economy. Figures are presented showing the extent to which economy can be increased by changing such factors as the carbureter adjustment, time of the spark, rear-axle ratio and speed of driving. A car that normally will go 21 miles per gal. under favorable test conditions at 20 m.p.h. was increased to 43 miles per gal. at 20 m.p.h. The study is not complete but has gone far enough to demonstrate its value. This progress report is presented to stimulate thought.

HIGH-compression engines for automobiles, Mr. Kettering predicts, are not far off if the petroleum and automobile industries cooperate in their development. An engine operating at high compression ratios, he points out, gives impressive gains in economy over the entire driving range, and without any sacrifice in smoothness. Mr. Kettering reaches this conclusion as the result of an extensive testing program of an experimental engine of 12.5 to 1 compression ratio. The tests were carried out both in the laboratory and on the road with the engine installed in a car.

This article contains vital, practical, interesting ideas for every automotive engineer. Exemplifying his own thesis that engineering presentations of all kinds must be made stimulating and thought-provoking if engineers expect to influence others, the author tells how engineers can increase their salaries, add to their prestige and get people to listen to them.

IN the following article, Mr. Hall says: There are two ways to develop more power from less engine - by improving current engines, and by a new start toward a more promising type. For lowest powerplant drag, use the barrel engine with cylinders parallel to the shaft. “You wouldn't shoot a bullet sideways.” Six barrel - engine mechanisms are appraised critically in this paper in order to find the best, which is also better mechanically than the crank mechanism. In a cross-head mechanism in which, pistons cannot cock, top speed may be 15% faster than with the crank for same combustion time, and there is almost no useless loading on bearings. Of all combustion systems, the choice narrows to four-stroke Otto cycle or two-stroke diesel. Specifications are given of a four-stroke gasoline engine using current poppet-valve practice, capable of delivering 3000 hp at 3000 rpm, weighing 2700 lb with 6 sq ft frontal area.

FULL cognizance of the fact that the power-weight ratio of a vehicle is the fundamental factor which no trick or gadget can possibly circumvent, was brought about by the formulation of the SAE Truck Ability Rating, Mr. Wolf reminds. A better power-weight ratio can be accomplished, he explains, by three expedients, singly or collectively, these being: increasing the power of the engine; conserving the power developed; and reducing the weight of any of the components making up the gross vehicle weight. Past and present practices covering the ratio of chassis weight to gross vehicle weight for 1935 and 1940 are analyzed in this paper; also horsepower to gross vehicle weight for 1931, 1935, and 1940. Some typical truck models are scrutinized for specification and design trends over the past ten years or more, emphasizing the horsepower and torque per pound of chassis weight, as well as the gross vehicle weight per pound-foot engine torque.

The Mos Controlled Thyristor (MCT) is a very promising switch device which combines the high power capability of thyristors and the low energy gate control of a MOS device. The MCT has high voltage and high current capabilities and its power dissipation depends on the losses due to turn-on, turn-off and conduction. This paper describes the potential of indirect liquid cooling to remove the waste heat generated while a MCT is operating at various power levels and switching frequencies. An MCT device dissipated 187 W. The switching mode was cooled to keep the junction temperature below 150°C by using the Venturi cooling technique.

The determination of component part failure rates is required for most military contracts normally during the early portion of the program definition phase. For new technology devices whose failure rates have not been established nor available in recognized military documents, it has been impossible to accurately predict the reliability of the system using these new devices. A technique developed by authors enables a prediction to be made for new state-of-the-art devices using a mathematical transfer model. This paper describes a mathematical transfer model using established failure rate data from bipolar integrated circuits (IC). These bipolar devices contain similar characteristics, basic materials, processes, testing, inspection, environmental, physics of failure, and application, to the new device. Failure rates for the new device, large scale array (LSA ) metal-oxide-semiconductor (MOS) are obtained through use of this model.

Recent trends in automotive electronics point towards a growing demand for sophisticated audio and video systems in new vehicles. These systems are being driven by several factors including a migration of consumer electronic devices to vehicles and a need to control these devices in the vehicle's driver and passenger environment. The incorporation of digital network buses, such as MOST (Media Oriented Systems Transport), build the digital data infrastructure in the vehicle for these advanced audio/video systems. However, additional considerations must be given to the constraints around the deployment of the audio and video devices into the vehicle and adapting them to the vehicle's digital infrastructure bus. This paper will explore these constraints and discuss some of the approaches that are being taken to deploy digital video systems on the MOST optical network bus in emerging vehicle multimedia applications.

Power electronics is playing an increasingly important role in vehicle systems. The voltage rating of automotive power electronics is predominantly determined by the transient immunity requirement, which considerably exceeds the maximum operating voltages of 12V and 24V automotive power systems, and imposes a large cost penalty. In contrast, the emerging 42V systems require a much improved bus voltage regulation to maintain system affordability. In this paper, we introduce a new class of transient voltage suppressors termed as MOSTVS, which provides a more accurately controlled clamping voltage than the conventional Zener diodes and MOVs over a wide range of current and temperature. The new MOSTVS concept, based on power MOSFET and polysilicon thin-film technologies, makes it possible to relax the breakdown voltage requirement of automotive power electronics and result in significant cost reduction.

IN analyzing the operation of aircraft-engine parts, the high-speed motion picture camera has many advantages over the older methods, which involved the use of vibration indicators, stroboscopes, and strain gages. High-speed motion picture studies have the advantages of forming a permanent record and of accurately evaluating transient conditions. Many subjects have been studied by means of high-speed motion pictures, some of which are here shown and discussed by Mr. Jackes.