Business: THE RADAR BRAKE

And Other New Auto Features To Come

To auto engineers and designers, the sparkling new cars in the showrooms are history. What excites them are the radical changes soon to come. When will all cars have brakes to stop a car automatically as it nears an obstacle? Are carburetors obsolete? How soon will the gas turbine replace the piston engine?

Some of the changes are soon to come. The automatic radar brake will be one of the most startling changes to be introduced by one automaker on 1957 models. The brake will be operated by a radar screen, built inconspicuously into the radiator grill. As the radar-equipped car approaches any object ahead, e.g., another car or a garage door, the radar screen will flash an impulse to the brakes, which will slow down or stop the car. The mechanism will be geared to take into account the speed of the car as well as the distance. For example, the radar car would be halted with a jolt if a car only a short distance ahead stopped suddenly. But if the slowing car were a few hundred feet ahead, the radar car would be braked easily. The radar brake can make electroni cally fast decisions for the driver who is inattentive or slow to react, can be canceled when necessary by stepping on the gas, e.g., if the driver decides to pass the car ahead. -

But the greatest engineering change in next year's models will be less spectacular; it will be the replacement of the carburetor by a fuel-injection system by at least one automaker. Long used in aircraft and racing cars, fuel injection has been thought too tricky and expensive for stock cars. But the rapidly rising cost of the new four-barrel carburetors has closed the cost gap while several practical stock-car systems have been developed. In present carburetors, gasoline is mixed with air, then sucked into the cylinders through the manifold. With a fuel-injection system, small pumps attached to each cylinder spray the fuel-air mixture under pressure directly into the firing chamber. With better engine breathing and more accurate fuel control, the system gives faster acceleration, particularly at low speeds, more effective horsepower and more gas mileage.

Fuel-injection systems, which may take years to reach all cars, will probably be the last major refinement of the present piston engine. The great change will be the turbine engine. But the first engine will probably not be a true gas turbine. It may well be a "free-piston engine," a combination of the piston engine and turbine. The idea of the engine is old, but only recently have automakers been able to eliminate many of the bugs. In the present engine, the pistons turn the crankshaft as the explosions in the cylinders drive them down, thus transfer power to the transmission and move the car. In the free-piston engine, there is no crankshaft. Instead, there are two pistons, at opposing ends of the cylinder, which force gas at tremendously high pressure into a turbine. The turbine, in turn, transmits power to the wheels through a simplified transmission. By eliminating the crankshaft and a complicated transmission, the free-piston engine cuts weight, cost and loss of horsepower by friction, thus is more efficient all around.