What Is a Small Block Engine?

Reviewed by

Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on November 15th, 2023

Reading Time: 4 minutes
Summary
  • A small block engine has small bores strokes, ports, and valves. Still, it’s capable of generating up to 5,800 rpm.
  • Small block and big block engines differ in terms of displacement, bore and stroke, and size and shape.
  • Small block engines are generally lighter, consume less fuel, and have cheaper repair costs compared to big block engines.

Car enthusiasts love to debate over what the better engine is: a small block or a big block engine. Just based on the name, many believe the big block engine is better, but size isn’t the only thing that matters when it comes to engines. In fact, you’d be surprised by just how much power a small block engine is actually packing.

What Is a Small Block Engine?

As its name suggests, a small block engine is a block engine with small bores, strokes, ports, and valves. It weighs a lot less than a big block engine, but it can generate up to 5800 revolutions per minute (RPM).

History of Small Block Engines

The first small block engines to hit the market were the Chevrolet Series D V8 engines. Produced from 1917 to 1919, they unfortunately had a short lifespan, but they encouraged other companies to produce their own version of the Chevy small block.

Soon enough, Ford released the powerful Flathead V8, which quickly became popular among mechanics and car enthusiasts alike. By 1955, Chevrolet debuted their new and improved small block engine called the “Turbo-Fire”, which was two times more powerful than the other small blocks on the market. People started calling it the “Mighty Mouse”.

It didn’t take long for General Motors (GM) to develop other versions of the small block engine, but the last of the original small blocks were discontinued in 2003.

A small block engine is a block engine with small bores, strokes, ports, and valves that weighs a lot less than a big block engine but can generate up to 5800 RPM. Image source: Trainguy1 | Wikimedia Commons

Differences Between Small Block and Big Block Engines

While small block and big block engines obviously have different sizes, that isn’t the only thing that sets them apart. Here are some examples of their other differences:

Displacement

Back then, a small block engine typically had a displacement of less than 400 cubic inches, while a big block engine could measure over 400 cubic inches. While this doesn’t necessarily mean a small block engine was less powerful, it did mean it had less air and fuel intake than an average big block.

Bore and Stroke

Unlike big block engines, small block engines have larger bores and smaller strokes. This means they typically have less displacement, but they can rev faster than big blocks.

Size and Shape

With just one look, you can probably tell a small block engine from a big block engine. A small block engine is physically smaller than a big block, and it also has a distinct V shape.

Pros of Small Block Engines

Don’t underestimate small block engines just because they’re small. They actually come with a lot of advantages that make them a popular choice for many drivers. Here are some examples:

Lighter

Small block engines are a lot lighter than big block engines, which means they can make a vehicle feel much lighter too. There’s less pressure on the front axle, making vehicles with a small block engine easier to handle and faster than vehicles with a big block.

Consumes Less Fuel

Lighter vehicles are typically more fuel-efficient than bigger vehicles, and small block engines are no different. With smaller cylinders, small block engines use up less fuel than big block engines, which is not only better for the environment but also for your wallet.

Less Expensive To Fix

Because they have fewer parts than big block engines, small block engines are also much cheaper to repair. You’ll have fewer parts to maintain too, so you can expect to save on both time and money when it comes to these smaller engines.

Cons of Small Block Engines

No engine is truly perfect, even if it’s as compact and cost-efficient as a small block engine. Here are some of its disadvantages:

Less Torque

While small block engines are great for sports cars, they’re a lot less practical for larger and heavier vehicles. Small block engines typically produce around 220 to 350 lbs-ft of torque, while big block engines can reach well over 500 lbs-ft of torque.

Less Horsepower

Small block engines aren’t all that great at producing horsepower too. With smaller bores and shorter strokes, they offer less horsepower than big block engines. A small block Chevy can produce around 145 to 370 horsepower, which pales in comparison to the average 430 horsepower of a big block engine.

Vehicles With Small Block Engines

As great as small block engines are, most of them have been overshadowed by powerful big block engines. However, this doesn’t mean small block engines weren’t popular in their own right. Here are some examples of popular vehicles with small block engines:

Some of these vehicles have unfortunately been discontinued, but you can still find some of them being sold for thousands of dollars. However, there are some that have stood the test of time, such as the Chevrolet Corvette and its 350 small block engine, which are still being produced to this day.

Small Block vs. Big Block: Which Engine Is for You?

People often debate over which engine is better, but the truth is that it really depends on what you’re looking for. Small block and big block engines both have their own pros and cons, so it all comes down to what you want from an engine.

If you want more power at the cost of pricier repairs, then a big block engine might be for you. However, if you want better acceleration and handling, then a small block engine is the way to go.

About The Authors
Reviewed By Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Tony Harlin is a Master Gas and Diesel Diagnostic Technician with over 18 years of experience. He works full-time at a large independent automotive shop as a driveability and repair technician working on all types of vehicles with a focus on diesels. ASE certifications include A1-A9, L1 and L2, as well as X1.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

Share
Published by
CarParts.com Research Team and Anthony Harlin, ASE Certified Master Automobile Technician