(Video) What’s the difference between a Bare Block, Short Block, Long Block, and Complete Engine?

We’re always looking for complete engines from companies such as CAT, Cummins, Detroit, Volvo, Mack, Ford, and GM. However, do you know what a complete engine actually includes? Do you know the terms: bare blocks, short blocks, and long blocks?

Today, we’ll break down the differences between all these terms. They are interchangeable between diesel and gas engines; however, we really only deal with diesel engines at DieselCore. Several components on a complete engine are different between the two, but there are also many that are the same.

Bare block

Let’s start with the basics…..a bare block. This is exactly what the name implies and it’s the most stripped down basic block. A bare block has none of the internals so it doesn’t have pistons, rods, or a crankshaft. Easy enough right?

Short block

Next, we have the short block. It’s a bare block, but now you add in the pistons, connecting rods, and a crankshaft. The block is considered short because it doesn’t have any cylinder head/s. Depending on the style of engine, this could include the camshaft if it is not an OHC engine.

Long block

Let’s move on to the long block. It’s a short block, but with cylinder heads. A long block adds heads, camshaft/s, and a valve train. There are a lot of components that could or could not be included as well including intake manifold/s, exhaust manifold/s, valve cover/s, oil pan, pickup tube, oil cooler, fuel filter housing, front cover, flywheel housing, etc.

Complete engine

Finally, we get to the complete engine. The complete engine includes everything. You know when your engine is running? If you take the whole engine out, that’s a complete engine. (We don’t advise taking your engine out when it’s running of course.)

A complete engine is a basic long block plus your fuel systems, turbos, electrics (alternator, starters, power steering system), all the tin (valve covers, oil pan, and front cover), and the ECM and wiring harness.

Many times, there are a few of the smaller components missing on a complete engine, which we can work with, but for a complete engine, the essentials need to be there which includes a good long block, all engine covers, the turbo and the complete fuel system.

Note: Complete engines are the form of engine that we like to get the most, and sometimes the only way that we will actually buy an engine.

Got engines?

So now do you know the differences between all the different engine blocks? At DieselCore, we’re always looking for good complete engines and core. If you have core to sell, please visit our website (DieselCore.com) for the latest buy sheet.