Chevy Puts Its Power In The Back

The most novel car to be introduced by Detroit this fall is Chevrolet's Corvair. This is General Motors' first entry into the compact car sweepstakes, and it is a rear-engined honey which represents real pioneering.

There was considerable eyebrow-lifting when the word got around that the Corvair would be a rear aluminum engine job. Some said that a rear-engine car of Corvair's size would tend to oversteer, that it would waver on windy days and wouldn't corner properly. Rear engines were fine, they said, for cars weighing less than 1,700 pounds, but for a 2,340-pound Corvair, well....

On the test track, I drove the Corvair in a range of speeds up to 85 mph, and the handling was beautiful. At medium high speeds she took flat turns smoothly. On rough gravel at 60 she held the road fine. And at 85 on open stretches and in steering situations there was no wander or shift.

One thing most auto companies don't like to talk about is acceleration performance. I clocked the Corvair, when the test driver took the wheel, at 18 seconds from standing start to 60 mph. We were in a Corvair with two-speed automatic transmission (the standard transmission will do this trick in 17 seconds). Accelerating at 50 mph in a passing situation the Corvair will travel 1,250 feet in 10 seconds. And from a standing start the Corvair will do the first 1,000 feet in 10 seconds.

When braked to the floor at 70 mph on a medium downgrade the Corvair showed no untoward effects. The stop was satisfactory and, best of all, there was no dip. One undeniable characteristic of front-engine cars is the dip or "dive" from fast braking, because the engine weight pulls the front end down. Late-model front-engine cars have antidive built in, but none can totally eliminate the characteristic.

I was aware that some rear-engine cars are downright noisy. With the windows rolled up to cut out road noise, I couldn't hear a sound from the rear in this one. A sound-absorbing bulkhead of fiber glass between the engine and the rear housing kept her quiet. And I was surprised not to hear the expected tire squeal on curves.

To achieve these good handling characteristics, Chevy engineered a weight distribution of 40% on the front axle, 60% on the rear; with a heavier, cast-iron engine this ideal weight distribution wouldn't have been possible. A second rear-engine problem—that of overloading the rear tires and causing front-end "wander"—was solved by use of Tyrex cord tires mounted on wider rims. With trucks and their heavy rear-end cargoes, four or eight tires are used; Corvair, with a smaller but similar problem, uses the wide rim and special tires inflated to 26 pounds; front tires carry only 15 pounds.

Corvair's weight distribution is also an aid in braking. A stopping car shifts its weight to the front, and with that rear-engine weight going forward the four wheels more equally share the braking job.

One interesting Corvair engineering feature is the independent suspension system for the rear wheels. The chief advantage of such a "swing" suspension is that it allows each rear wheel to hop independently on bumps and thus reduce the number of jolts transmitted to the frame and passengers.

The aluminum rear engine has its six pistons opposed in a horizontal plane, like so many fists punching a common punching bag. Its displacement is 140 cubic inches. Because this engine is not deep and is circular in shape, it is called a "pancake." You can sit on the ridge of the rear deck opening, reach over and work on this engine. Some call this "hind-end servicing." The engine isn't shiny at all because it is covered with weatherproof black sheet metal.