What’s the difference between long block and short block engines?

What’s the difference between long block and short block engines?

         shortandlongblockIf you’ve ever talked to a technician or browsed the internet for an engine, you may have heard the terms “long block” and “short block” used. So what’s the difference between “long” and “short” in this context? These terms are mostly used to describe what’s actually included in the engine package you’re purchasing. There are lots of complicated, mechanic-lingo heavy explanations of the differences between them, but what you’re most likely concerned with is understanding differences in forthright, layman’s terms. Allow us to present the relevant facts to you.


Short Block


The short block is the meat and potatoes of engine packages. It’s typically comprised of just three things:

  • The block
  • Crank
  • Pistons

As you can see from the picture, the short block will resemble something like the skeleton of a car engine. Contrary to what the name might suggest, the short block is not any smaller in size than the long block. In fact, they’re the exact same block. The words “short” and “long” refer only to the package deal. A short block engine package is a “shorter” deal; it includes a short list of components and usually a shorter warranty. There may be slight variation in what different companies offer as their “short block engine,” but the term generally connotes an engine in its “bare bones” form, without all of the extra (but necessary) components.


Long Block


The long block engine is not quite your complete package. An electric control unit, the transmission, and possibly some additional necessary wiring will not be included in either a short block or a long block. You may or may not need new versions of these parts, so make sure you understand what actually needs replacement (if you think you may need to replace these parts too, see the “turn-key engine” section below).

So what’s included in the long block? The long block engine package provides everything that’s in the short block engine and more. Here’s what you may expect to find in a long block package:

  • The block
  • Crank
  • Pistons
  • Camshaft
  • Cylinder heads
  • Valve-train
  • Oil pan (sometimes)
  • Valve covers (sometimes)

Keep in mind, this list represents what you’ll find in your typical long block package. Always be sure to check the specs of the engine you’re looking at before you go ahead and make the purchase (unanticipated costs can be a pain in the wallet!). Generally, the long block is considered the complete internal engine. But external parts such as the oil pan, valve covers, exhaust and intake manifolds, harmonic balancer, timing cover and flywheel may have to be purchase separately. This, of course, is something to keep in mind while calculating your costs.


What’s the cost difference going to be?

There’s really no good answer to this question. The only given is that shorter will be cheaper and longer will be more expensive. Any engine seller or manufacturer will tell you that price difference between short block and long block engines is entirely relative to make, model, and year. A good idea is to write the details of your car’s engine and call a two or three local or online engine services asking for quotes on both the short block and the long block engine for your car.


Which should I buy?

While short block engines are cheaper than long block, they’ll also require the purchase of additional parts and more installation time (the additional parts you buy would come preinstalled on a long block engine). If you already have some of the smaller parts included in a long block engine, you may be better off buying a short block and gathering the extra little bits and pieces. You’ll have to weigh the costs. If you don’t already have any minor parts that will be compatible with the engine you’re looking at buying, the long block will be your most cost-effective option. But if you can identify that the only really defective piece in your engine as the block itself and/or the crank and pistons, then the short block package is by far your best and cheapest route.



Another thing to consider in choosing between a short block engine and a long block engine is warranty. As a trend, the entire package warranty of a long block engine tends to be longer and better than the short block’s warranty. But it gets more complicated than that. A conventional warranty should cover all parts included in your purchase (again: always, always, always check the specs!). So in the case of a long block engine purchase, you shouldn’t have to worry about the functionality of the individual parts. But if you buy a short block engine and have the other parts installed separately, those parts obviously won’t be covered in your warranty. What also will not be covered is their installation (the parts themselves may be completely fine but they could be improperly fitted to your engine), which brings us to our next point.


If I buy a short block engine, should I install the additional parts myself?

The answer for anyone who does not have prior experience in car mechanics is a clear, resounding NO! The last thing you want to do to your wallet and your poor vehicle is cause something to malfunction, either right off the bat or down the road (literally!), simply because you didn’t have the experience to put it in right. This is neither wise nor safe.

Hiring a professional mechanic will almost always be the safest route, but if you’re a DIY, garage junkie type of person and you’ve put car parts together before, this might be something you could consider. Here’s a couple “musts” for you:


No. 1: get your hands on a repair manual for your specific car

Of course, we realize that the DIY type often coincides with the anti-directions/instruction manual mentality, and we get that. We respect you. But this is something you really, really, really don’t want to mess up, even just a little! You may still have a repair manual from when you bought the car or you may need to order it off the internet (you can usually find them online; sometimes you can just download them). Just get your hands one can keep it close if you even want to think about installing this yourself!

No. 2: know when to put on the brakes

Figuratively, that is. If you’ve started the installation process yourself and find yourself lost, or have an uneasy feeling about how you put it together, don’t be afraid to stop where you are and get professional help. Hiring someone always beats having your vehicle suddenly break down and then hiring someone.


Addition factors

Maybe you’re still not sure whether short block or long block is the way to go. There are a couple other things that could factor into your decision making, so if you’re not entirely sure by now, consider a few of these…


No. 1: check the carburetor

In case you aren’t familiar with it, the carburetor basically blends air and fuel in your engine. This will typically be a circular-ish device (there’ll be a wide cylinder built somewhere into it). It may look something what’s pictured below.


The reason you may want to check the carburetor is that if you’re block needs replacing, it’s not entirely unlikely that your carburetor has gone south as well. You’re carburetor could be completely fine, but it’ll be worthwhile to just check on, if you can locate it.

If you do find that your carburetor needs replacement, see the section below about “turn-key engines.” Neither the carburetor nor any of the parts listed below will be included in a short block or long block engine.

No. 2: throttle shafts


It’s possible that your throttle shafts (see pic) may need replacement. This is a fairly inexpensive part, but it’s one more thing that adds to your costs. Locate your throttle position sensor and check to see the shafts and everything else are functioning as they should.


No. 3: if you have an overhead valve engine…

In an overhead valve (OHV) engine, the valves are put over cylinder head. Because of the structure of this type of engine, more frequent maintained is often required. It’s possible that the head may need to be worked on or other miscellaneous parts replaced.

No. 4: miscellaneous defects

Pop open that hood and do a little reconnaissance. See any rusting, worn linkages, or cracked shrouding? If your engine’s been around for a while, you may have some issues that don’t signify the end of the world, but could stand to be fixed. If you see enough of these (and they bother you enough) you may want to get those parts replaced at the same time you replace your block.

This may have opened up a whole new can of worms for you. If you find that any of the above parts need replacement, you may need to consider a different engine package entirely, which brings us to…


The “turn-key” or “crate” engine


A turn-key engine (also called a “crate engine”) is one that’s all set up and ready for you to slap it into your vehicle, turn the key, and start driving. This may be worth buying if you’re also in need of any parts (like those listed above) that are not part of the actual engine block. A typical turn-key engine package should include the following:

  • The block
  • Crank
  • Pistons
  • Connecting rods
  • Camshaft
  • Cylinder heads
  • Pushrods
  • Gasket
  • Valve-train
  • Oil pan
  • Valve covers
  • Rocker arms
  • Intake manifold
  • Throttle pedal
  • Ignition coil packs
  • Spark plugs
  • Oxygen sensors
  • Airflow sensors
  • A lot of other odds and ends…

It’s a long list, but the gist is that the “turn-key” is the complete package. Just as the long block = the short block + more, the turn-key = the long block + everything else. The issue is that you probably don’t need to replace everything. So how does one decide whether it’s more cost-effective to buy it all or to buy just the parts needed?


To buy or not to buy a turn-key engine

Determining whether to buy a turn-key engine or a block engine comes down to the same sort of calculations as determining whether to buy a long or short block. Calculate the price difference between a turn-key and a long block package, and add to the cost of the long block package all of the following factors: costs of additional engine parts (carburetor, shafts, etc.), cost of the separate installation of these parts, and the value (by personal estimation) of the comprehensive warranty you won’t get on the long block + the extra parts. Also, since the turn-key engine comes as a complete unit—ready to pop in and drive—installation is going to be much cheaper/less time-consuming (whether you’re doing it yourself or hiring a mechanic) than the block engine. Make sure to include this in your calculation.


Final exhortations

Hopefully by now you have a feel for what package best suits your needs. If not, you can always find a mechanic service locally or online who can tell you more. As you begin to consider adding more to your engine package your wallet will begin to ache, so determining the most cost-effective route is crucial. Everyone’s situation is a little bit different. The key is to determine what your vehicle really needs done, calculate your costs accordingly, and pick the package that, for you, will have the minimum amount of unnecessary replacements and will also require the minimum amount of additional replacements. That’ll be your best deal.

Of course, we here at SWEngines are all about great deals. We hope this article has been a help to you and we also would like to help you in finding the engine you need. Head over to www.swengines.com and fill out the quick, easy form to get a quote on your engine. With a free 3 Year Parts and Labor Warranty, you can’t go wrong. Buying an engine can be complicated. We’re here to make it easier on you!


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