Chevrolet 3.8L Engine: Evolution and Overview

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While the V8 engines often get all the glory, GM depended on a small V6 to power many of its vehicles for nearly 40 years. It was the 3.8L engine that could!

The GM 3.8L V6 powered many Buick, Pontiac, Chevy, and Oldsmobile vehicles beginning in 1975. The engine was initially produced by Buick and was based on the aluminum 3.5L V8 Buick used in the early sixties. The engine would undergo many variations but would reach over 25 million vehicles.

With the end of the internal combustion engine all but on the horizon, many people are touting the notorious power plants that have helped build the automotive industry to the heights it enjoys today. While the “stars” might be big-block or small-block V8s, many sensible, less powerful motors have appealed to American buyers. One such example might be the GM 3.8L V6. In an age of fuel economy worries, where consumers needed to watch their pennies, this stalwart, reliable V6 helped save the day, finding its way into various vehicles. GM didn’t tout the engine as a powerhouse, and many people felt it was a lackluster offering, but it consistently lasted for over three decades. So, we would like to pay homage to the GM V6, an engine that showed up, did its job, and paved the way for many of the supercharged motors we take for granted today.

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The Chevrolet 3.8L Has 60s Roots

The early days of the GM 3.8L V6 have their roots in the early sixties when Buick developed an all-aluminum 3.5L V8 engine for use in the Skylark. Dubbed the “Fireball” engine, the motor was the first manufactured V6 in the United States, which GM used exclusively as a Buick engine.  The 3.2L Fireball had a cast iron design (mainly because it was cheaper to build) than its aluminum V8 counterpart. Still, it shared several components that proved to be less than appealing to many.

The 90-degree spacing between the cylinders and the crank pins powering opposing cylinders gave the engine an uneven firing pattern, which many people felt produced a rough idle. When GM approached American Motors to build the engine, one AMC executive remarked that the engine was “as rough as a cob.” In the mid-sixties, the engine was used sporadically in some Buick and Oldsmobile models. Still, with Americans reveling in the power of V8 engines and muscle cars, GM felt it no longer needed a V6. Eventually, GM sold the rights to the engine in 1967 to would sell the rights to the engine in 1967 to Kaiser-Jeep, who had no problems using it as a powerplant for its Jeeps and SUVs.

GM Needs A V6 Engine

Unfortunately, an Arab oil crisis, only a few years later, would force GM to reconsider the Fireball V6 and buy back the rights to the engine from AMC in 1974, when the company needed a V6 to power many of its models. GM increased the bore to 3.8L in 1974 and began producing the smaller motor for the ‘75 model year Buicks. While the automaker described the engine as “spirited” in its sales brochures, it had a reasonably pathetic power output of only 110 hp. Yet, GM remained committed to the engine, finding ways to place it in other models, and before long, it appeared as the standard engine in many Olds, Chevy, Pontiac, and Buick models.

The engine became so prevalent that GM invested time and money to develop the motor further by fixing the crankshaft issues, using a split-pin design to create an even firing pattern. The modification helped remove the “roughness” of the previous engines and paved the way for GM to use this engine as its standard motor for much of the late seventies.

GM Plays With Turbo

While the 3.8L engine quickly became the V6 of choice for many GM models, the designers also sought ways to harness more power. In 1978, GM launched its T-Type family of engines, significantly boosting power outputs by turbocharging the engine. Initially, the new “turbo” version was found on cars like the ‘80-’81 Chevrolet Monte Carlo. However, it enjoyed a longer life on other models in the Buick lineup, like the LaSabre, Regal, Century, and Riveria.

GM continued to play with the engine, giving it sequential fuel injection and a wasted spark distributor-less ignition along with other performance enhancements in the mid-eighties, bumping the power outputs to around 245 hp (which made the V6 a potent contender) for many other V8 engines. The intercooled turbo V6 found its way to various vehicles, including the 1986 - 87 Grand National and GNX. When Car and Driver tested the car, the reviewers found it to run a 4.7 second 0 - 60 mph. Autoweek drove the model and declared that Buick “had reinvented the muscle car.”

The 3.8L Gets Front-Wheel Drive

.While the Turbo-charged engines might have regained some of the muscle car glory for GM, the need for muscle cars was not as strong in the eighties, as the companies needed to compete against the rising tide of imports. GM knew that to compete in the changing global market, they would need to convert to front-wheel drive vehicles, and so adopted the 3.8L for that purpose.

By 1988, GM modified the 3.8 liter with a new balance shaft, on-center bore spacing, and other improvements to power much of its new lineup. During this time, the engine would soon receive the “3800” moniker that it became famous for. The LN3 found its way into most Buick and Oldsmobile models (along with the Pontiac Bonneville through 1990). When GM refined the engine in 1991 with more forced induction (a supercharged engine), the new engine was given an internal code of L27 (Series 1), producing 170 - 174 hp, which made it a viable powerplant for much of the lineup. Even though the L27 would go through a couple of supercharger revisions, it had still not seen its best days.

The Series II Hits The Streets

GM changed almost everything about the engine in 1995 but kept the displacement at 3.8 liters. The deck was shortened, requiring the piston rods to be smaller and the crankshaft. New cylinder heads were fashioned with larger valves and a revamped intake manifold, resulting in higher compression and power outputs. The Series II engine produced 205 hp with better fuel economy than anything GM had produced up to that time. It would not be long before GM slapped the motor into everything it could to convince consumers that their hard-earned dollars were not wasted in buying a fuel-efficient vehicle from an American car company.

Despite their prevalence, these Series II engines did have some flaws. GM issued a recall in late 2009 due to the tendency of the motor’s valve cover gaskets to leak, creating a fire hazard. The plastic intake manifold also wreaked havoc on owners, often cracking around the EGR passage, resulting in locked-up motors. The problems forced GM to revise most of the gaskets for the engine, correcting the problem, but many of these Series II engines continue to suffer issues.

The Series III Revision

In 2004, GM redesigned the 3800 V6 again, giving it electronic throttle control (throttle by wire) and a new fuel injection system. The plastic intake manifold was replaced with a more durable aluminum one, and bulked-up connecting rods helped lower emissions even further. GM offered the engine in primarily Pontiac Grand Prix, Buick Lucerne, and Lacrosse vehicles from 2004 - 2008 in both naturally aspirated and supercharged versions.

Despite the revisions, including larger fuel injectors and electronic throttle body fuel injection, it became clear that the end was near for the revered 3800 V6. In 2006, it was only offered a couple of vehicles, down from eleven models in 2005. Pontiac offered the supercharged and naturally aspirated versions in 2006, which the sales brochure touting 260 hp, but only offered on the base Grand Prix and GT models.

The End Of An Era

By 2008, GM decided that the 3800 V6 had outlived its usefulness, and knowing that there were issues with the Series II, they moved on to other projects. In 2009, a more spirited 3.9L V6 would replace the engine, boosting power and fuel efficiency. Yet, even though GM initially discarded the engine but then resurrected it for almost 35 years, it proved its ability to perform.