The Pontiac 326 Cubic Inch V8

This small displacement engine packed a lot of punch

Pontiac engine
1963 Pontiac 326 CID Engine. Photo by Mark Gittelman

There is a reason why we used to preface automobile engines, like the Pontiac 326, with the manufacturer's name. While many cars today share engine platforms (pop the hood on a Buick, Cadillac, Chevy, etc., and you'll likely see the same liters and cylinders), it wasn't always that way. Back in the '60s and '70s, the individual divisions took great pride in manufacturing their own unique engines. With that said, it's widely believed that GM had a few ground rules.

Power Ruled

One popular belief is that GM wanted the Chevrolet Corvette to have the most powerful engine. At times this created a problem for the Pontiac Motor Division. This meant they had to make a few negative gain adjustments, so their engines would fall in line behind the Chevy products.

In the early 1960s, Pontiac designed and deployed the 326 CID (cubic inch displacement) V8. Interestingly enough, this would fall just one cubic inch short of the 327 found in the 1963 split-window C2 Corvette. Since classic car collectors interested in Pontiacs will often find the 326 under the bonnet, we decided to provide a little more information about this common engine.

Classic Pontiac V8 Engines

Raise the hood on any classic Pontiac built from 1963 through 1967, and you'll have a 50/50 chance of seeing a 326 installed in the engine compartment. However, it's even more common to see them in the midsize Pontiac Tempest and Lemans models. The small displacement eight-cylinder engine came with a two-barrel carburetor standard. The four-barrel carburetor as optional equipment wouldn't surface until the following year.

The bigger cars, like the flagship Bonneville and the Pontiac Catalina, are often found with the larger displacement 389 V8. Pontiac offered the 389 engines in a wide variety of horsepower ratings. Not only did the engine carry a two- or four-barrel carburetor, it also featured compression ratios of up to 10.5:1. If you're really lucky, maybe your classic Pontiac has the 368-horsepower tri-power option Super Duty 389 cubic inch Trophy Motor.

Versions and Specifications for the 326 CID

When manufacturers first started to drop this small V8 into cars in 1963, they only offered a two-barrel carburetor version. The engine provided excellent fuel economy at nearly 20 miles per gallon on the highway. Despite the lack of fuel, the horsepower numbers remained respectable. In the inaugural year, the 326 produced 260 horsepower

In 1964, Pontiac built a high output version of the 326. Finally, buyers could get a four-barrel carburetor and true dual exhaust on the small but powerful V8. However, it was a bump up in the compression ratio that made the biggest difference. The high-output engine produced 280 horsepower at 4800 RPMs. It also supplied 355 ft-lb of torque at 3200 RPMs. In 1967, they squeezed out another five horses by increasing the redline to 5000 RPMs.

The Shining Moment 

In 1967, Pontiac released the all-new Firebird. The car cost $200 more than its sister ship, the Chevrolet Camaro. The base engine for the launch of the Firebird was a 3.8-liter V6. However, the most popular choice that year was the 326 V8 engine. In fact, out of the 64,000 eight-cylinder Firebirds built in 1967, more than 46,500 of them had the 326-cubic-inch motor.

Just as it did the year before, Pontiac offered two varieties: the 260-horsepower two-barrel and the quad-barrel-equipped high-output engine at 285 horsepower. Buyers did have a shot at ordering an optional 400 V8 rated at 325 horsepower. This engine replaced the 326 for the 1968 model year in all of the Pontiac vehicles that offered eight-cylinder power.