Chrysler’s Slant-6 was a strangely tilted engine that refused to die – Jalopnik

In the late 1950s, as American motorists discovered the benefits of small and efficient cars, Chrysler knew it had to get in on the action. As a result, it set up separate projects to develop both a new Valiant car line and a new engine to power those machines. Somewhere along the way, however, something got lost in translation, and the new car’s engine bay wasn’t big enough to handle the new engine.

The six-cylinder engine – with an inline configuration and a displacement of 170 cubic centimeters – was too high for the hood to be closed, and also too long with the front-mounted water pump. A larger mill of 225 cubic inches was also in development. Now Chrysler could have redesigned the engines or the cars, but instead the engineering team had a stroke of genius.

Instead of installing the engine with the cylinders pointing straight up, they tilted it 30 degrees as if it were half of a V-shaped engine. This was not the first time a car manufacturer had achieved this, as Mercedes-Benz used a tilted inline six-cylinder engine in the legendary 300SL in 1954. But it did make Chrysler’s engine a legend in its own right, gobbling up millions of miles in millions of vehicles — including what may be the most reliable American car ever built.

The original 170-cubic-inch Slant-Six engine debuted in the compact 1960 Plymouth Valiant, although the mill didn’t always use its now-famous name. Before that caught on, Plymouth tried calling them 30-D engines (because of their 30-degree tilt). Regardless, the smaller engine turned out to be a bit too small in real applications. It only made 117 horsepower and 155 pound-feet of torque, which was too much of a trade-off for the improved efficiency.

Also launched in 1960, the 225 cubic inch Slant-Six started life producing 140 horses, supplemented by a nearly 30% increase in torque over its smaller brother, raising the bar to 215 pound-feet. Major upgrades to the engine included an all-new block with an increased deck height, a longer stroke and a revised crankshaft. Note that the same block, with a shorter throw, was used with a 198 cubic inch Slant-Six. It replaced the 170 cubic inch engine in 1970 and remained in production until 1974.

The 225 Slant-Six wasn’t perfect, of course, but a series of updates kept it alive in Chrysler vehicles well into the 1980s. You could still find the engine in some passenger cars until 1984 and in certain trucks until 1987. In addition, the engine was produced for a variety of marine and industrial applications until 1991, when it was eradicated – mainly for emissions reasons. (Maybe we can bring it back now that emissions standards are a thing of the past.)

Chrysler’s Slant-Six engine also inspired one of the most stunning concept cars of the jet age: the 1960 Plymouth Granted, it is tuned to today’s NASCAR specifications, which are very different from what is expected for the next generation of racing. But it did take the

The concept was created by Virgil Exner, one of the masters of automotive design, who wanted to recreate the basic layout of the Indy cars of the era. After seeing the Slant-Six, he moved the driver’s position from the center of the car (like in a racer) and placed everything far to the left side of the vehicle, including the hood scoop, the small windshield, and the vertical rear stabilizer.

The original Plymouth XNR has come quite a journey in the later years of its life. Owned by the Shah of Iran, it survived the Lebanese Civil War in the 1980s and was eventually restored and sold at auction in 2012 for a cool $935,000. The XNR is now owned by the Paul and Linda Gould Collection and was also briefly featured in the recent Amazon series based on the video game “Fallout”.