he Chrysler Small Block engine, also known as the Chrysler LA series, is one of the most influential engine families in the history of American automobiles. Introduced in the late 1950s, this engine design has powered everything from everyday passenger cars to high-performance muscle cars. It has earned its place in automotive lore, known for its reliability, adaptability, and performance. While it may not be as widely recognized as the more famous “Hemi” engines, the Chrysler Small Block engine deserves its own spotlight due to its unique contributions to Chrysler’s success and the automotive industry as a whole.
The Origins of the Chrysler Small Block Engine
Predecessor to the Small Block: The Chrysler “Hemi” V8 Engines
Before the introduction of the Small Block engine, Chrysler was already famous for its large, high-performance engines, particularly the legendary Hemi V8 engines. These engines, such as the 392 Hemi V8, were designed to deliver impressive power outputs and were primarily used in Chrysler’s larger vehicles and performance-oriented models.
However, by the late 1950s, Chrysler recognized the need for a smaller, more efficient V8 engine that could be used in a wider range of vehicles, from mid-size sedans to compact cars, without sacrificing performance. Thus, the Small Block engine was born.
The Birth of the LA Series Engine
The first Chrysler Small Block engine, the “LA” series, debuted in 1958. This new engine was designed with a smaller overall displacement than Chrysler’s larger V8 engines, which allowed it to be used in a wider range of vehicles. The “LA” series designation stands for “Light A,” a reference to the engine’s smaller size compared to the full-size “B” series V8 engines, which Chrysler also produced during the same era.
The initial engine, the 318 cubic inch (5.2 liters) V8, was relatively modest in terms of power output compared to Chrysler’s larger V8 offerings. Still, it offered excellent performance for its size, with a balance of power and fuel economy that appealed to a broad market of drivers.
Key Developments and Evolution of the Chrysler Small Block
The Chrysler Small Block engine underwent several key developments throughout its production run, which spanned over four decades. These changes helped the engine stay competitive with the rapidly evolving automotive market.
The 273 and 318 Cubic Inch Engines
The first Chrysler Small Block engine to be produced was the 318 cubic inch (5.2-liter) V8, which was used in various Chrysler, Dodge, and Plymouth vehicles. In the early years, the 318 engine was the primary version of the Small Block engine and found its way into vehicles like the Dodge Dart and Plymouth Valiant.
However, as the performance-oriented muscle car market began to grow in the 1960s, Chrysler sought to offer higher-performance variants of the Small Block engine. This led to the introduction of the 273 cubic inch V8, which had slightly more power than the original 318.
The 340 and 360 Cubic Inch Engines
By the mid-1960s, the Chrysler Small Block engine had evolved to include even larger displacement options. In 1966, Chrysler introduced the 340 cubic inch (5.6-liter) V8 engine, which was engineered for high-performance applications. The 340 engine was designed for the Chrysler “muscle car” line-up, and it was used in vehicles like the Plymouth Barracuda and Dodge Challenger. The engine was known for its high-revving capabilities and excellent throttle response.
In 1971, the 360 cubic inch (5.9-liter) engine replaced the 340 as the largest displacement option in the Chrysler Small Block engine family. The 360 was still a relatively compact V8, but its increased displacement allowed for more torque and power, making it suitable for a wide range of vehicles, including performance models and heavier vehicles like trucks.
Technological Advances: The 318 “LA” Series Evolution
Throughout the 1970s and into the 1980s, Chrysler made numerous improvements to the 318 engine, which remained in production for several decades. These improvements included changes to the engine’s heads, pistons, and other internal components, which helped improve performance, efficiency, and emissions.
The development of the 318 engine became particularly important as Chrysler moved toward compliance with the increasingly strict emissions regulations of the 1970s and 1980s. The engine was modified with more efficient carburetors, improved cylinder heads, and better fuel economy features while still maintaining a good level of power.
By the late 1980s, the Chrysler 318 engine had become one of the most popular and widely used small-block engines in Chrysler’s lineup. It was found in everything from the Dodge Ram 1500 to the Plymouth Grand Voyager minivan.
The Final Iterations and the Introduction of the Magnum V8
In the 1990s, Chrysler introduced a new line of engines, known as the Magnum V8s, which were based on the original LA series Small Block but included updated technology such as fuel injection, better combustion efficiency, and improved performance. The Magnum V8 engines (including the 318 Magnum) became popular in both performance and truck applications and carried the legacy of the Small Block engine into the new millennium.
Although the LA series Small Block engine was officially discontinued after 2003, its influence can still be seen in modern Chrysler engines, which continue to be based on similar designs.
Specifications of the Chrysler Small Block Engine
The Chrysler Small Block engine lineup is known for its compact size, reliability, and adaptability. The key specifications of the different Small Block engines varied, but they shared common characteristics. Below are the primary specifications and features of the most notable iterations of the Chrysler Small Block.
318 Cubic Inch (5.2-Liter) V8
- Displacement: 318 cubic inches (5.2 liters)
- Bore x Stroke: 3.91 inches x 3.31 inches
- Compression Ratio: 9.2:1
- Horsepower: 230 hp (varied by application)
- Torque: 280 lb-ft
- Fuel Delivery: Carburetor (later models had multi-port fuel injection)
273 Cubic Inch (4.5-Liter) V8
- Displacement: 273 cubic inches (4.5 liters)
- Bore x Stroke: 3.63 inches x 3.31 inches
- Compression Ratio: 9.5:1
- Horsepower: 235 hp (varied by application)
- Torque: 290 lb-ft
- Fuel Delivery: Carburetor
340 Cubic Inch (5.6-Liter) V8
- Displacement: 340 cubic inches (5.6 liters)
- Bore x Stroke: 4.04 inches x 3.31 inches
- Compression Ratio: 10.5:1
- Horsepower: 275 hp (varied by application)
- Torque: 355 lb-ft
- Fuel Delivery: Carburetor (later models had multi-port fuel injection)
360 Cubic Inch (5.9-Liter) V8
- Displacement: 360 cubic inches (5.9 liters)
- Bore x Stroke: 4.00 inches x 3.58 inches
- Compression Ratio: 9.1:1 (varied by model)
- Horsepower: 245 hp (varied by application)
- Torque: 340 lb-ft
- Fuel Delivery: Carburetor (later models had multi-port fuel injection)
These small-block V8 engines were known for their relatively compact size, making them easy to install in a wide range of vehicle chassis. Despite their smaller size, they were able to produce competitive horsepower and torque, particularly when paired with the right transmission and drivetrain.
What Classifies an Engine as a Small Block?
The term “Small Block” refers to an engine family that has relatively smaller physical dimensions and lower displacement compared to its larger counterparts, such as the “Big Block” V8s produced by Chrysler and other manufacturers like Chevrolet and Ford. A small-block engine typically features a smaller bore and stroke, along with a more compact overall design. While the specific criteria for what constitutes a small-block engine can vary by manufacturer, it is generally understood that small-blocks are more efficient in terms of fuel economy, weight, and compactness.
Small Block engines are typically characterized by their “shorter” block design, which results in a shorter engine deck height compared to larger Big Block engines. The result is a more compact and lighter engine that can be more easily packaged into smaller vehicles, giving manufacturers the flexibility to use these engines across a broad range of car and truck models.
Which Cars Were Powered by the Chrysler Small Block?
The Chrysler Small Block engine found its way into a variety of vehicles over the years, from performance-oriented muscle cars to family sedans and trucks. Some of the most famous vehicles powered by the Chrysler Small Block include:
Muscle Cars and Performance Vehicles
- Plymouth Barracuda: The Plymouth Barracuda was one of the first vehicles to offer the Chrysler Small Block, particularly in the form of the 273 and 318 engines. It became a muscle car icon and one of the first vehicles to capitalize on the muscle car craze of the 1960s.
- Dodge Dart: The Dodge Dart, particularly in its “Swinger” trim, featured a range of Small Block V8s, including the 318, 340, and 360 engines. It was an affordable yet powerful vehicle that catered to the performance-minded consumer.
- Dodge Charger: The Dodge Charger, which debuted in 1966, was another vehicle that utilized the Chrysler Small Block engine, particularly in its early years. The 318 and later the 360 engine were available in various Charger models.
Full-Size Sedans and Trucks
- Dodge Ram 1500: The Chrysler Small Block engine, particularly the 318 and 360 versions, became a popular choice for the Dodge Ram 1500 series pickup trucks. These engines offered a good balance of performance and fuel efficiency for consumers who needed both power and practicality.
- Chrysler Newport: The Chrysler Newport, a full-size sedan produced in the 1960s and 1970s, was available with a 318 Small Block engine. The engine offered smooth performance and respectable power for a full-size sedan.
- Plymouth Voyager: Chrysler also used the 318 Small Block engine in some of its minivan models, such as the Plymouth Voyager and Chrysler Grand Voyager, during the 1980s and 1990s.
Other Applications
- Dodge Dakota: The Dodge Dakota, a compact pickup truck introduced in the mid-1980s, used the 318 and 360 Small Block engines in various trim levels. These engines provided good towing capacity and overall performance for a truck of its size.
- Chrysler Imperial: Although the Chrysler Imperial was primarily a luxury car, certain models offered the Chrysler Small Block engine as an option for buyers seeking more affordable performance.
What Are Chrysler Small Blocks Best Known For?
The Chrysler Small Block engines are best known for several key attributes:
- Versatility: These engines could be found in everything from muscle cars to family sedans and pickup trucks, making them one of the most versatile engine families in Chrysler’s history.
- Performance: Despite their smaller size compared to the “Big Block” engines, the Chrysler Small Block engines offered excellent performance, particularly in the muscle car segment. The 340 and 360 engines were particularly revered for their power and high-revving capabilities.
- Fuel Efficiency: The relatively smaller displacement of the Small Block engines allowed for better fuel efficiency compared to larger Big Block engines, making them ideal for vehicles that needed a balance between performance and economy.
- Durability: Chrysler Small Block engines were known for their robustness and reliability. They could endure high mileage without major issues, which helped make them a popular choice for everyday drivers.
Conclusion
The Chrysler Small Block engine is an iconic powerplant that played a pivotal role in the success of Chrysler’s vehicle lineup for several decades. From its humble beginnings in 1958 to its role in the development of muscle cars, trucks, and family sedans, the Small Block engine has proven itself to be versatile, reliable, and performance-oriented.