Unraveling the Mystery: What is a 350 Bored 30 Over Called?

Published by Dustin Babich on

A 350 bored 30 over is called a 355 engine. It is a popular engine size often used in street rods, muscle cars, and other high-performance vehicles.

The 350 bored 30 over, also known as a 355 engine, is a type of engine that has been modified to increase its displacement by 30 thousandths of an inch (0. 030″). It is a popular choice among car enthusiasts and is commonly used in street rods, muscle cars, and other high-performance vehicles due to its increased power and performance.

This engine size provides an ideal balance between power and efficiency, making it a great choice for those looking to enhance their vehicle’s performance. In this article, we will dive deeper into what a 350 bored 30 over engine is, how it works, its benefits, and some considerations to keep in mind when installing one.

Understanding Engine Boring

Engine boring is the process of increasing the size of an engine’s cylinder. This is done by removing some of the material from the cylinder walls. The term ‘350 bored 30 over’ refers to an engine with a 350 cubic inch displacement that has been bored 0.

30 inches over its standard size. Engine boring is an important process because it can increase the engine’s power and performance. By boring an engine, the internal volume of the engine’s cylinders can be increased, allowing for more air and fuel to be burned during combustion.

This means that the engine can produce more power. However, boring an engine too much can cause problems, so it’s important to have the work done by a professional.

What Is A 350 Engine?

The chevrolet 350 engine is famous in the automotive industry. It is commonly called a “350 bored 30 over”. This engine is a v8 type, featuring eight cylinders in a v-shape. The 350 engine has been at the heart of some of the most legendary muscle cars.

The engine has a horsepower range of 195 to 375 and torque range of 260 to 415 lb-ft. it’s a versatile engine, which is why it’s been produced for over 30 years. The 350 engine featured forged internals, aluminum intake manifold, and 4-bolt main cap.

READ ALSO  Why Does My Impala Say Service Stabilitrak? 5 Solutions to Fix It!

Such specs are what made it a performance engine. The 350 engine found applications in both street and race cars. The 350 engine still remains a popular choice for car enthusiasts who want the perfect combination of power and speed.

What Does It Mean To 30 Over Bore A 350 Engine?

When a 350 engine is 30 over bored, it means the engine has been enlarged beyond its original size. Overboring is the process of making the cylinder walls bigger, which allows for larger pistons to be used. This results in a larger displacement and, in turn, increases the power output.

Overboring can also impact engine performance, both positively and negatively. Too much overboring can reduce the engine’s reliability and lifespan, while small overbores can improve the engine’s fuel economy and overall performance. A “30 over” bore is a common overboring increment used by many engine builders.

However, it is important to consult a professional before overboring an engine, as it can drastically affect the engine’s performance and lifespan.

The Benefits Of A 350 Bored 30 Over Engine

A 350 bored 30 over engine refers to adding 30 thousandths of an inch to the diameter of each cylinder. This modification is common in small block chevy engines, and it offers numerous benefits. One of the main advantages is improved engine performance due to better airflow and increased compression.

This, in turn, leads to an increased power output. Additionally, a 350 bored 30 over engine can also gain greater fuel efficiency, as the engine can now burn fuel more efficiently. Moreover, it enhances the longevity, and durability of the engine, which is an added advantage.

This upgrade is popular with performance enthusiasts who are looking to squeeze the best performance out of their engines and achieve a better driving experience.

How Can You Determine If Your Engine Is 350 Bored 30 Over?

Determining if an engine is 350 bored 30 over requires professional inspection and tuning. Key indicators include higher displacement, power and engine noise. During an engine inspection, mechanics evaluate valve lift, connecting rod length and cylinder spacing. This helps to determine the engine block’s original bore capacity and whether the current bore is within safe limits.

READ ALSO  Toyota Tacoma Drive Shaft Replacement: A Comprehensive Guide to Boosting Performance

Considering performance, reliability and longevity, it’s best to consult a professional before making any modifications to an engine’s bore size. A trained mechanic can inspect the engine, identify any issues and provide the best course of action to follow.

Professional tuning can increase power, improve fuel efficiency and extend the engine’s lifespan. So, if you want to ensure the best performance of your engine, it’s important to rely on an expert engine inspector and tuner.

Frequently Asked Questions For What Is A 350 Bored 30 Over Called

What Does 350 Bored 30 Over Mean?

When an engine block is bored and stroked, it means it has been machined to increase its displacement.

How Does Engine Displacement Affect Performance?

Engine displacement is directly proportional to power. More displacement means more power and torque.

What Are The Advantages Of A Bored Engine?

A bored engine results in more power, torque, and responsiveness. It can also improve fuel efficiency.


To sum up, a 350 bored 30 over refers to a modified engine that has increased its displacement by enlarging the cylinder bore by 0. 030 inches. The process is commonly performed by car enthusiasts who want to boost their engine’s horsepower and torque capabilities, as well as to improve fuel efficiency.

Understanding the terminology is crucial for drivers, especially those who want to modify their vehicles or purchase a car with the same modifications. While there are other ways to modify engines, the 350 bored 30 over method has been a favorite amongst car enthusiasts for years.

Whether you’re a car enthusiast or a casual driver, knowing the basics of engine modifications can give you an advantage when it comes to purchasing or modifying a vehicle. Keep in mind that before making any modifications, consulting with a mechanic or engine specialist is crucial to ensuring the long-term health and performance of your engine.

Dustin Babich
Categories: FAQ

Dustin Babich

Dustin Babich

As the passionate author behind Automotivesimple.com, Dustin Babich is a knowledgeable expert in all things automotive. With a deep understanding of car tools, equipment, engines, and troubleshooting techniques, Dustin Babich shares invaluable insights, practical tips, and effective solutions to empower readers in overcoming car-related challenges.


Leave a Reply

Avatar placeholder
As an Amazon Associate, I earn from qualifying purchases. This will not charge you any extra cost.