1960 saw the introduction of Chrysler’s famous Slant Six engine in the Plymouth Valiant with a gross horsepower rating of 101 ponies. The straight-sixes the company used before 1960 were awful, and Chrysler needed another engine for the happening Sixties.
The development engineers leaned the engine 30 degrees to the right, leaned the transmission 30 degrees to the left, and were able to get an approximately even weight balance in this fashion, hence the “Slant Six” name. The 170 cubic inch (round off to 3 litres) production design had extremely large main bearings which meant very low engine stressing, and the Slant Six started setting testing records in performance and durability right away. These results were mirrored in the Chrysler, Dodge and Plymouth customer population, with the Slant Six getting a reputation as being an engine that you couldn’t kill, even if you abused it. Ordinary citizens would run their engines up to 200,000, 300,000 miles with regularity. And by Sixties standards it got pretty good fuel mileage as well.
Increasing the size of the engine to 225 cubic inches and the horsepower rating up to 160 did nothing to decrease its longevity. One thing it couldn’t do, however, was run clean enough (with enough horsepower) to pass modern emissions standards.
The last Slant Sixes were produced for cars in 1984, for trucks in 1987, and, finally, in 1991 for marine use.
COPYRIGHT Autosavant.net – All Rights Reserved