What’s The Difference Between a Short Block and a Long Block Engine?

When rebuilding or modifying your diesel engine truck, the first thing you need to decide is the engine that will power your vehicle, how “complete” it is upon acquisition, and whether you opt for a short block or a long block. Do you want something that’s easy and quick to install, or perhaps an engine that allows a great deal of customization? 

If you need to modify your diesel engine to increase its performance and longevity, contact Choate Engineering Performance at (901) 553-9847 or leave a message on our website.

Short block vs. long block 

Despite their names, short block and long block engines have nothing to do with length, rather their main difference is “how complete they are” upon acquisition. For instance, a short block includes the most basic block with connecting rods, pistons and crankshaft, whereas a long block also has these components, plus cylinder heads, camshaft and valve-train. 

Pros and cons of a short block 

Because it has fewer components, it is usually cheaper than a long block and allows for greater customization. But on the flip side, it requires extra assembly work and installation time and you need to buy other parts that must be tuned for your short block. 

Although brands may offer slightly different packages, most short block engines only include the block and the rotating assembly, which comprises the pistons, rods, and crankshaft. Also, they can either come balanced or not. 

Another thing to keep in mind is that only the block is warrantied. 

Pros and cons of a long block 

Because it already includes parts that are already tuned, it is closer to being plug-and-play. Additionally, the block and its components are both included in the warranty. 

But since a long block includes more parts and is more “assembled,” it is slightly more expensive than a short block. Another caveat is that it does not allow for great customization, or better yet, it eliminates a lot of the fun that comes with building a diesel engine. 

Other related terms

When building or rebuilding a diesel engine, you’ll probably also hear the following terms: 

Turn-key engine. Also called a complete engine, it comes fully assembled that all the installer needs to do is to fit it into your vehicle, and you to turn the key and drive off. 

In general, it is a basic long block that includes the fuel system; turbos; the electricals such as the starter and power steering system; and the tin components like the covers, oil pan, front cover, and the ECM and wiring harness. 

However, some brands do not include smaller components on their complete engine, although in general, it has all the essentials that allow for plug-and-play. When we say “essentials,” we are referring to the engine covers, the turbo, and the fuel system.

Deluxe long block crate engine. This is just another term for a turn-key engine.

Crate engine. As its name suggests, it is a fully assembled replacement engine that comes in a crate. For instance, a turn-key engine that a mechanic can drop right into your vehicle’s engine bay as soon as it arrives on their doorstep. 

Bare block. This is actually the most basic, stripped-down version of an engine block. In short, it has no internal components such as pistons, rods or crankshaft.

What is the right engine block? 

The right engine block depends on several factors such as the level of customization you want, the model of your vehicle and its component’s compatibility with a block, your budget, and what you want to achieve with the modification. 

In general, a long block engine offers better performance and longevity because its parts come pre-installed, making it less likely to malfunction due to errors during the fitting process. In addition, its components tend to wear out evenly, which minimizes the replacement cost. 

However, not all long blocks are compatible with your vehicle. That’s why you need a diesel engine expert like Choate Engineering Performance should you decide to make some engine modifications. Our mechanics will ensure that your long block is compatible with your auto’s electronic control unit and transmission system. They also stick to the best practices during the fitting process to ensure excellent performance and minimize wear and tear. 

Meanwhile, a short block engine is ideal if you’re seeking a greater degree of customization since you can choose the parts (and brands) you can install. And with quality parts and accessories and correct fitting process, a short block may even perform better than a long block. 

Final word 

Whether you choose a short block, a long block, a plug-and-play engine, or something that offers a great deal of customization, you need a machine and repair shop that uses the latest technology and best practices to ensure that your diesel trucks are modified, rebuilt or repaired the right way the first time. 

 Visit Choate Engineering Performance to learn more about our services.