When it comes to large engines, there are a few key varieties to choose from: big blocks and small blocks. Unfortunately, figuring out which block is big or small is a difficult task, especially since there is no single universal standard to adhere to. Even standards offered by individual automobile manufacturers seem to evolve over time, especially as new materials are developed. Even the displacement of an engine is not a surefire way to tell the difference between small blocks and big blocks.
The best way to differentiate small blocks from big blocks is to compare the two side by side, but only from within the same generation and make. For example, comparing a few early 1980s Chevy blocks side by side should be an effective way to tell which engines are formed from a small block and which are made from a large block. The small block engines will generally be smaller in physical size, even if only by a few inches on each and every side.
Small block engines are generally found in larger vehicles and/or high-performance vehicles, and blend a combination of performance and reasonable weight while large block engines tend to be substantially heavier and capable of generating more power. The smaller block size translates into lighter overall weight in most cases, and that is important for engineers designing automobiles for many reasons.
Lighter engine blocks require less structural components, and negate or at least mitigate the need for balancing considerations. Handling characteristics are very sought after in modern vehicles, and engine weight and distribution of that weight are important factors in handling. This makes small block engines highly desirable for those with a need for power but also a lust for handling and maneuverability characteristics.
Ultimately, small block engines are also desirable from a price standpoint since they represent a compromise between low weight and high power. Low weight translates into lower prices, due to shipping concerns and manufacturing needs, and potentially high performance increases the number of applications that small blocks are appropriate for. Large cars, sports cars, and even many pickup trucks and other heavy-duty vehicles come with small block options that represent a balance between price and performance/capability.
The smaller physical size of the block means that there is less room between cylinders, which are the shafts that the pistons ride up and down in to generate power that is eventually transmitted to the wheels via the transmission. Smaller blocks have less size to allow for ‘fatter’ cylinders, or cylinders that are wider in diameter. This also means that the cylinder walls are smaller than they would be on a comparable large block of similar bore (cylinder diameter) and design. Thinner walls indicate a lower tolerance for extended stress, and a lower overall service lifetime in many cases.
- What is a Big Block Engine?
- What is a Two Stroke Engine?
- What is a Supercharged Engine?
- What is a V6 Engine?
- What is a 350 Engine?
