Plymouth’s first six-cylinder car in 1933 was a bit of a misfire, but the company quickly adjusted.

Introduced in the summer of 1928, the low-priced Plymouth was a solid success for the  Chrysler Corporation, marching up the sales charts to compete with Ford and Chevrolet. Among the superior features boasted by Plymouth were four-wheel hydraulic brakes, an exclusive in the low-priced field. Another innovation in 1931 was Floating Power, Chrysler’s patented engine mounting system that allowed the engine to rotate on its axis of mass, reducing vibration.

But when Chevrolet introduced a six-cylinder engine in 1929 and Ford introduced the 1932 V8, the four-cylinder Plymouth was in danger of falling behind. Chrysler asnwered back, launching the Plymouth Six in October of 1932 as a 1933 model. Here, Plymouth was an early adopter of the familiar industry practice of announcing the year’s new models in the previous autumn.

Responding quickly to the Chevy and Ford challenges, Chrysler borrowed the six-cylinder engine design for Plymouth from the sibling DeSoto brand. A straightforward L-head, the Plymouth six featured a bore and stroke of 3.25 inches by 4.125 inches for a total displacement of 189.8 cubic inches. While smaller in displacement than its competition, the six was rated at 70 hp at 3,600 rpm at the standard 5:1 compression ratio. An optional Red Head cylinder head boosted the compression ratio to 6.5:1 and the output to 76.5 hp.

Chrysler also announced $9 million in improvements to Plymouth’s Lynch Road plant, buying 90 minutes of airtime on the ABC Radio Network to promote the new Plymouth Six to its 7,200+ franchisees (Plymouths were sold by Chrysler, Dodge, and DeSoto dealers) and to its retail customers, too. An agressive print campaign in magazines and newspapers accompanied the Plymouth Six rollout.

Barney Oldfield with a 1933 Plymouth Six

However, the new Plymouth PC model, as it was known internally, did not get the reception Chrysler was expecting. While sales were fair, the volume was less than anticipated. The trouble was soon diagnosed: As the Chrysler engineers laid out the PC, the wheelbase had been shortened from the 112 inches of the previous four-cylinder PB to just 107 inches, giving the car a stubby appearance unbecoming of a six-cylinder automobile. Also, the angles of the radiator, windshield, and doors weren’t fully integrated, adding to the awkward look.

Chrysler quickly responded again in the spring of 1933, rolling out the Plymouth Six PD with a 112-inch wheelbase and smoother styling. Meanwhile, the PC received a one-inch bump in wheel base to 108 inches, and an additional model, the PCXX Standard Six, was introduced, combining the PC’s short wheelbase with the styling of the PD. Yes, the ’33 product line was confusing, and it was one more example of how, for the Chrysler family’s parts and service personnel, life was often complicated.

Despite the missteps, the quick adjustments allowed the Plymouth division to enjoy an exceptional year. Production rose from 180,000 cars in 1932 to more than 298,000 cars in 1933—in the midst of the worst economic depression in the nation’s history. Now Plymouth was solidly in third place in the low-priced field, trailing only Chevrolet and Ford. And while the car got off to a bumpy start, the Plymouth Six’s engine enjoyed a long and successful career. With periodic updates and displacement increases, the engine remained in production through 1959.