Despite their names, both engine types are similar in size. They differ only in the components they carry. A short block engine package typically includes the engine block, crank and pistons. The term short block comes from the short list of components in the engine, which usually come with a short warranty.
The long block engine includes all parts of the short block package with the addition of cylinder head, camshaft and valve train.
Most aftermarket and replacement engines can be ordered as short blocks or long blocks. But there are many other factors that influence which type of engine to put in a particular vehicle and a particular budget.
A turnkey or crate engine is a fully assembled engine that is typically shipped from the manufacturer to the installer in a crate. All the installer has to do is attach it to the vehicle, turn the key, and start the car. Turnkey engine packages typically include throttle pedals, spark plugs, airflow sensors, and various other small parts in addition to the parts that come with the long block.
If you need a new engine, you can buy a complete drop-in engine from the manufacturer or get it from an automotive machine shop. Sourcing from an independent shop or dealer may save you money and extend your warranty. If you are purchasing an engine from an independent dealer, you should know what is included in the short block and long block engine packages.
short block engine
The short block engine is the lower end of the vehicle’s engine. This includes the cylinder block and other critical parts of the engine such as the crankshaft, cam pistons and connecting rods. These parts are also called rotating assemblies. Some short blocks may come with camshafts and timing belts, as there is usually a slight difference in the engine builder company’s packaging. All short block engines require additional parts such as gaskets, cylinder heads and oil pumps and must be purchased separately.
The Short Block Engine is perfect for those who want to teach themselves the engine building process. Building a short block engine is a great learning experience and offers a more complex, hands-on approach to engine swapping.
long block engine
The Long Block Engine is in some ways a complete version of the Short Block. Features camshafts, lifters, valve trains and cylinder heads in addition to pre-assembled blocks. Longer blocks may also come with oil pans, water pumps and valve covers. Long blocks are typically used when diagnostics indicate that the vehicle needs an engine overhaul.
Although it has more components than the short block, the long block engine is not a complete engine package. Long blocks do not include parts such as fuel systems, intake manifolds, exhaust manifolds, or electrical components. If you need to replace these components or all other parts of your engine assembly, consider ordering a “turnkey” engine.
Some people confuse short-block and long-block engines with small-block and big-block engines, or call them interchangeably. There is a big difference between these terms. A discussion of engine sizes, starting with the classification of small block engines or large block engines. Short block or long block refers to the number of assembly parts it contains.
Short block engines are generally cheaper than long block engines. As of 2021, long block engines cost between $1,500 and $5,000, while short blocks cost around $1,000 to $3,000. The price difference also depends on the make, model and year of the car the engine is designed for.
However, the short block engine requires the purchase of additional components that come standard with the long block. Shorter blocks take extra time to install as all the pieces have to be installed. Longer blocks are usually a better bargain when you factor in the extra components required and labor costs.
Long block warranties are typically longer and more comprehensive than short block engines. The warranty covers only the parts included with the original purchase and does not cover any additional components installed on the short block. Consider having the engine installed by a professional mechanic as neither engine type’s warranty covers problems resulting from a bad fitting.
Additional parts required for short blocks can be purchased with different warranties depending on the company from which they were purchased. However, if you do buy a short block engine, understand the parts warranty and any installation warranties your mechanic may offer to guarantee the work.
Choosing the Right Engine Block
Long block engines generally provide better and more reliable performance than short block engines. Since the long block has more parts pre-assembled, malfunction due to mistakes in the fitting process is less likely to occur. Additionally, components contained in long blocks wear evenly, minimizing replacement costs.
As with any pre-assembled auto part, not all long blocks will work well with each make and model of vehicle. To match the performance of the stock engine, it is necessary to ensure that the installed long block is compatible with the vehicle’s electronic control unit and transmission system.
On the other hand, the short block engine has a wider range of exterior parts to choose from. If you invest in quality parts and accessories, you can expect shorter blocks to perform better than longer ones. For example, consider the cylinder head assembly, which directly affects the horsepower output of the engine. Unlike long blocks, short blocks do not have a pre-installed cylinder head. You can freely choose the head according to your performance. A good head with a good short block can make more power than the stock engine.
If the old unit has critical internal parts damaged beyond repair, but other external parts are still functioning, consider using a shorter block than the remanufactured engine. If these parts are damaged and the combined cost of buying the short block and additional components approaches the cost of buying the long block, consider getting the long block for an engine swap instead.
Understanding the differences between short block and long block engine packages will help you find the perfect fit for your vehicle. Get and compare short block and long block engine quotes from multiple dealers before you buy. The quote you receive should include specifications and estimated installation costs for each engine type.
Extensive diagnostic testing is always recommended on a failing engine to avoid unnecessary replacements in the future. Understand why the engine failed in the first place, then fix the problem when a professional mechanic replaces the engine. If the engine fails due to overheating, the fan relay and coolant temperature sensor may be failing. Until this major issue is fixed, you risk being stuck with another seized engine instead of fixing the original.
https://www.autolist.com/guides/short-block-vs-long-block-engine Short block engine and long block engine