What is a 350 Bored 40 Over?

Published by Dustin Babich on

A 350 bored 40 over is an engine that has undergone modifications to increase its cubic inch displacement by 40 thousandths of an inch per cylinder, resulting in a larger overall engine size. This process is known as “boring” the engine, and is done by removing a small amount of material from the cylinder walls to increase the size of the cylinder bore.

A 350 bored 40 over engine can provide increased performance and power over a stock engine, as it allows for greater airflow and improved combustion. It is a popular modification option for those seeking more power and performance from their engine.

Understanding The Terminology

A 350 bored 40 over refers to an engine built using a specific combination of modifications. The number ‘350’ denotes the engine’s displacement in cubic inches while ‘bored 40 over’ refers to an increase in the cylinder bore diameter by 0.

040 inches. This alteration contributes to an overall improvement in the engine’s performance, horsepower, and torque output meaning the vehicle can go faster, tow more and accelerate better. However, the downside to this increased power output is that it may reduce the engine’s lifespan, and it may require more frequent maintenance.

The History Of 350 Bored 40 Over Engine

The famous 350 bored 40 over engine started in the 1960s as a high-performance option for muscle cars. It evolved over time, with multiple iterations including different blocks and pistons. Despite newer engines being produced, the 350 bored 40 over remains popular among classic car enthusiasts.

The engine provided an optimal ratio of power and reliability, making it a solid choice for enthusiasts looking to create a car that could be driven daily or for weekend cruising. Its versatility made it attractive to a wide range of motorists as they could easily upgrade, modify or tune the engine to meet their specific needs.

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Today, the 350 bored 40 over engine remains an important piece of automotive history admired for its unique combination of speed and dependability.

How Does A 350 Bored 40 Over Engine Work?

A 350 bored 40 over engine is a type of engine that has been modified to produce more power than a stock engine. It works by enlarging the size of the cylinders through the process of boring. This allows more air and fuel into the engine, which leads to more power.

The engine also has upgraded components like the camshaft, heads, crankshaft, and pistons, which all work together to produce power. This type of engine is popular among car enthusiasts who want to improve the performance of their cars. Compared to other engine types, the 350 bored 40 over engine is known for its reliability, durability, and ease of maintenance.

Performance Upgrades For Your 350 Bored 40 Over Engine

A 350 bored 40 over engine is a modified version of the original 350 chevy engine. The modifications involve boring the cylinders 0. 040 inches larger to increase the displacement and enhance the engine’s power and performance. There are various performance upgrades one can make to this engine, depending on their needs.

For instance, one can opt for a high-performance camshaft, high-flow cylinder heads, or a stronger intake manifold among other modifications. The choice of upgrade largely depends on the desired power output and the application of the engine. For instance, if you plan to use the engine for street performance, you may opt for a milder camshaft and lower compression ratio compared to a race engine.

Maintaining Your 350 Bored 40 Over Engine

Maintaining your 350 bored 40 over engine is crucial to ensure peak performance and longevity. Regular oil changes, tune-ups, and monitoring fluid levels will prevent damage and keep your engine running smoothly. Use high-quality fuel additives and avoid over-revving your engine.

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A clean air filter is vital for optimal function. Regularly inspecting belts and hoses will prevent costly repairs. Finally, follow manufacturer recommendations for service intervals and don’t ignore warning signs such as strange noises or low oil pressure. By following these tips, you can keep your engine running at its best for years to come.

Frequently Asked Questions Of What Is A 350 Bored 40 Over

What Does It Mean To Bore An Engine 40 Over?

Boring an engine 40 over involves increasing the cylinder size by 0. 040 inches, resulting in increased engine displacement and more power.

What Is A 350 Engine?

A 350 engine refers to a small-block v8 chevrolet engine that was first introduced in the 1967 camaro, and has been used in various gm vehicles over the years.

How Much Horsepower Does A 350 Bored 40 Over Have?

The horsepower of a 350 bored 40 over engine varies depending on the upgrades made, but it can produce up to 500 horsepower in high-performance applications.


This engine upgrade requires extensive planning and consideration, but it’s a profitable investment for those who want to enjoy a more powerful and thrilling driving experience. The 350 bored 40 over is an ideal upgrade for car enthusiasts who want to enhance their car’s performance and keep their engines running for a longer time without any hassle.

Dustin Babich
Categories: Knowledgebase

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.


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