If there is one decision that needs to be made when building a car that seems to cause the most stress for many enthusiasts, it’s deciding what variation of motivation to place under the hood. Any guy worth his torque wrench first dreams about building a fire-breathing monster that will be the envy of everyone at the cruise night. He inevitably imagines pulling into his parking spot while the 12.0:1 compression ratio and 300-degrees of duration in the camshaft not only fill the air with raw fuel and a thump that can be heard from all corners of the gathering. He loves the idea, but soon realizes that the combination might not be practical for his situation.

With this reality now fully understood, he has decided to tame things down a little. Instead of a 12.0:1 compression ratio, he opts for something a little more street friendly, like 10.5:1. And that long duration camshaft? Well, it needs to tighten up a little bit. But, he has another decision to make: choose the individual parts and build the engine himself, or take a good hard look at a crate engine.


Our very own Project Blank Slate getting it’s Custom LSX engine installed.

Deciding whether to build or buy and engine is one of the most important questions an enthusiast can ask themselves when it comes to powering the projects they work on. If you are going to build an engine from scratch, you will need a myriad of specialty tools, a decent recipe of parts, and a good machine shop in your back pocket. Now, if you already have things like a rod bolt stretch gauge, piston ring filer, and so on, then you most likely will be building your own. For the guy who can install an engine, but maybe not build one from scratch, then buying an assembled unit might be the best option.

Let’s face facts, deciding on a theme for a car, and then actually following through can be a daunting task. There are so many aftermarket options available, and having to come up with an engine combination that will build the power you want, and actually stay together for more than a few miles is a legitimate concern.

We’re not here to tell anyone that building an engine is better than buying a crate engine, or vice-versa. The choice is ultimately yours. But, we do want to inform you well enough so you can make a solid decision of which is your best option.


A good usable block is the basis for any engine build. If you are custom building an engine, you need to locate one and that is getting harder to do. If you buy a create engine, they find the block.

Scratch-Built Bruiser

To start this comparison, we’ll first talk about custom building. Unless you have an in-depth working knowledge about how each part of an engine works together, selecting the parts and actually building an engine may seem intimidating. If you do not, jump to the section about buying a crate engine. We’re not saying that you couldn’t build the engine of your dreams, but unless you have a good friend – or engine builder that you trust – it will be a daunting task. The stress could also become overwhelming, and you might actually lose interest in your project and abandon it. We don’t want to see that happen.

If you feel this is the best option for you, do your research. Before you do this, make sure you’re confident in the information you gather. A lot of guys have been known to get advice from people on forums, and while there is some good information to be had, there is also information out there that should not be out there. We suggest finding a good machinist in your area, and talk to him before you buy anything. You can find a good machinist by talking to other enthusiasts about their experiences with shops local to you. Trust your gut, if you do not get a warm and fuzzy feeling when you’re talking to someone, shake their hand and move on. If you’re not comfortable before the process begins, you will never be comfortable.

Sticker Shock Will Happen

Once you are comfortable with a particular shop, now you can talk about the parts he recommends, and what he charges for his services. Take for instance, just making sure the block is usable. That entails – at a minimum, cleaning and Magnafluxing. We checked with a couple of local machine shops, and we found an average price of $300.00 to clean, Magnaflux, check the deck surfaces, align hone, bore the cylinders .030-inch, and install cam bearings.

Many procedures have to be completed before any engine can be assembled. Are you willing to pay for each of them if you custom build?

Even after you have the engine block ready for assembly, you still need to figure the cost of your parts. We know not everyone will choose the same parts, but we’ll generalize here. If you have a crankshaft and connecting rods, plan on spending roughly $60.00 to remove the old pistons, another $100 to recondition the connecting rods. You’ll spend approximately another $85.00 to Magnaflux and polish the crankshaft. Even after that is ready, you’ll once again be reaching into your soon-to-be empty wallet – and we’re just averaging here – to give someone anywhere from $150 – $300 for pistons, and then give the shop $60.00 to install the pistons on the connecting rods. Have you noticed that things are adding up rather quickly?

Now you need bearings, gaskets, an oil pump, timing chain, and other small parts that you will initially not think about but will eventually learn about when you need them and don’t have them. Let’s just make it an even $125.00. Now, you could buy a rebuild kit that usually gets you most of what you need for around $275.00 or more, depending on the options you get. So far, you have around $900 – $1,000 in the engine, and you still need heads, intake, and carburetor.

If you want to use factory cast heads, the rebuild expense can be high. If the heads can even be rebuilt, unlike this cracked unit.

If you have a set of cast-iron heads you want to use, you can have them rebuilt. Figure on $75.00 to disassemble and Magnaflux both heads, and $80.00 to resurface the heads and eliminate any warpage. But wait, there’s more. We have never come across a cylinder head being rebuilt that didn’t need at least two or three of the exhaust guides replaced ($10 each plus cost of guide. Usually, all exhaust guides will need to be replaced) Let’s just say $80.00 as an average. If you need to replace any valves, there goes another $15 each. Let’s be conservative and say you need to replace four valves. There goes another $60.00. You wouldn’t put the used valves back in without giving the heads a valve job, would you? Cha-ching, add $200.00.

By the way, if the cylinder heads are not compatible with unleaded fuel, a set of hardened valve seats will need to be installed. At roughly $20.00 each, that comes to a whopping $320.00. Have you started cringing yet? Depending on how in-depth you have the shop get with the refurbishing of your cylinder heads, you could end up with anywhere from $850.00 – $950.00 in a pair of used heads. That’s nearly the cost of a new set of Edelbrock Performers, and if you go that route, the E-heads will run you slightly more than $900.00. Since that’s right around the same cost as rebuilding a used set of stock heads, why would you rebuild a cylinder head that will not perform as well as the Edelbrock head?

Aluminum heads are not only better performing than stock cast-iron units, but they are also available in ready-to-run form. And, the price is at least similar – if not less expensive – than having your stockers rebuilt.

Okay, let’s add the intake. We’ll concede that a decent, used, dual-plane intake can be had at a swap meet for $100.00 to $150.00, so we’ll go with that. As far as a carburetor, a new Holley will run anywhere from $300.00 to $500.00 for a good street-use carburetor. Have you done the math yet? So far, our outline comes to an average total of $2,375.00. That is, if you can assemble everything yourself. If not, figure on another $600.00 to $700.00 to assemble the engine. Like we said, this is just a rough average, and we’re sure that there would be a few surprises pop up that will need addressed, and more of your money.

Drop-In And Run

We’re sure that you guys have all thought about a crate engine for your project. Even if it was just for a fleeting moment, the thought crosses everyone’s mind at some point. The option of purchasing a complete, ready-to-go engine can be a blessing for those who aren’t inclined to build an engine themselves, or pay someone else to build it for them.

But, not all crate engines are the same. If you check out how many places you can find a crate engine and the options available, the choices can be staggering. When researching crate engines, you’ll find that you can get a long-block, a short-block, or a complete engine. A short-block is not a complete engine, and will typically include the camshaft, pistons, connecting rods, timing chain and gears, and a crankshaft. They do require the end user to install items like an oil pump, cylinder heads and intake, carburetor, tin work (valve covers, timing chain cover, and oil pan), and gaskets.

Choosing a crate engine like this one form Chevrolet Performance eliminates the time spent looking and waiting for parts, the the inevitable time it takes the machine shop to finally get to your needed machine work, and then the hassle of assembly – especially if you do not have the specialized tools.

A long-block is everything from a short-block, and includes the cylinder heads and intake. If you are replacing an engine in your ride that has gave up the ghost, a long-block is a viable option. You can transfer all of the ancillary pieces from your new small- or big-block boat anchor, and install them on the long-block. Now, you can also buy a complete engine, at that will be the focus of this article.

Before you give out those digits on your wallet-sized debt creator, you have some decisions to make. For starters, are you replacing the engine in your cruiser, or does your ride see street and strip duty? Being honest with yourself about what you really need will ensure your get exactly that.

A Good Recipe

Like we said, not all crate engines are equal. When you are doing your research, pay attention to what parts are used in each engine you look at. Do you want or need steel, H-beam connecting rods? Are forged pistons a must, or will hypereutectic be sufficient for your ride. Also, if you plan to build your own engine, the outline below could also be used a s guideline for you guys as well.

Engine Blocks

Most economically priced crate engines will use a seasoned factory block, much like when custom building an engine. So the actual block is really a moot point. If you are adamant about having a four-bolt main, then that should be a question you ask of the company supplying your engine. There are many choices when it comes to aftermarket blocks, and if that is something important to you, again, do your research to see who has what.

Reciprocating Assemblies

Over the years, the sheer numbers of different reciprocating pieces have increased exponentially. It wasn’t that long ago, that dropping a crankshaft from a 400 small-block into a 350 block was a fairly new idea. Today, it is second nature for almost everyone taking on a 350 small-block build. Like crankshafts, there are dozens of different piston and rod combinations for the small-block alone. You just have to decide whether forged parts are necessary, and decide between connecting rods that come as an H- or I-beam.

Camshaft and Valvetrain

There’s no question that roller camshafts are the hot ticket, and some crate engines include them as standard equipment. But if that’s what you want, clarify that with your supplier. More often than not, a flat-tappet camshaft is used, and that helps lower the cost of the engine. This advice is applicable to you whether you build or buy an engine. If you are not looking for something that’ll spin past 6,000 rpm on a regular basis, a roller camshaft could be overkill.

Cylinder Heads

When it comes to cylinder heads, there are countless options to choose from. Today, purchasing cylinder heads that flow almost as well as anything once used on a racecar is as easy making a phone call or online purchase. Once again, being honest with yourself about what you truly need can save you a lot of money, and even help with performance.

A huge decision revolves around whether to use iron heads or aluminum heads. Bench racing sessions have debated the difference of each for as long as anyone can remember. One side of the discussion says you can get away with a higher compression ratio with aluminum heads since they dissipate heat better. Others claim that iron heads make more power because they keep the heat in the chambers. Whatever you feel is true, we did a quick search at Summit Racing, and found new, cast-iron cylinder heads from Chevrolet Performance that were ready to run, and cost $320 a piece. A set of aluminum heads by BluePrint Engines would run you $505 each. Both are great heads, and it comes down to your budget, and preference.

Induction Systems

When it comes to getting air into an engine, you have many possibilities. Choosing an intake, with so many options available, we will focus on single-plane and dual-plane. Which is better for your application? That depends on your application.

You need to choose an intake that will work in the RPM range your engine will be running. For instance, the RPM range of the intake should match the RPM range of the camshaft and the valvetrain. Street cars typically run best with a dual-plane intake. That is because the power band begins much lower in the RPM range. A typical dual-plane intake will have a power band that begins at roughly 1,500 to 1,700 rpm, while the power band of a single-plane intake is usually rated to begin at around 3,000 rpm and up. If you’re building an engine that will typically see street use, do you know where your engine RPM will be 90-percent of the time? We guarantee it’s not above 3,000 rpm.

Choosing a carburetor is a decision that confronts everybody in the hobby at some point. whether it’s for a street or race vehicle, carburetors come in different styles and sizes, so selecting one can seem complicated. Fortunately, you can check out how to do that by checking out this article.

Warranted Weigh In

Another thing to really consider when decided whether to build an engine or buy a crate engine, is a warranty. There are not many local machine shops that will custom build an engine for you, and then give you a warranty that matches those of a crate engine. That being said, if there is an issue with your engine, many machine shops will help you remedy the situation, but it might cost you some money.

A reputable supplier of crate engines typically offers some sort of warranty. For instance, Edelbrock includes a two-year/unlimited-mileage warranty on all applications. According to the 2017 Chevrolet Performance catalog, if you order one of their non-E-ROD Connect & Cruise packages or Performance Parts Engines, you get a 24 month or 50,000-mile warranty, and their E-ROD engines get you a 36 month or 50,000-mile warranty. These are only two examples of crate engine manufactures supplying a warranty, and whatever company you choose to patronize, ask if they include a warranty, many do.

When it comes to deciding whether to build an engine or buy a crated version, there really is no incorrect choice. The decision comes down to what makes you comfortable. If you can gather and assemble the parts you need to build an engine that will be reliable and deliver the kind of performance you are after, I say go for it. If building a custom engine seems a little unnerving, there is no shame in buying a crated version.

Below are some simple tips you might want to consider when making your decision:

We suggest you pay attention to any engine’s torque output, not the big horsepower numbers. It seems like everyone is enamored with how much power an engine makes, but here’s something to think about. If we have two engines that deliver the same amount of horsepower at 5,000 rpm, but one has substantially more torque at lower RPM, which is better? Remember, having more torque at a lower rpm can get the vehicle moving more quickly. If you’re using tall gears (numerically low), that is a real benefit.

Consider the cylinder’s bore size. Has it been or will it need to be bored .040, .060-inch or even larger? Cylinder wall thickness needs to be a consideration. If the cylinders have been over-bored to an extent the walls are getting thin, issues like high running temperature, ring seal, and oil consumption can present themselves.

Is your car running any vacuum-operated accessories? If so, camshaft selection is going to have a dramatic effect on the amount of vacuum that an engine produces. While a big camshaft might sound cool when you enter the cruise night or car show, in the long run, having a slightly milder camshaft will deliver better drivability, and even better fuel economy.

Finally, know the engine builder. This is true whether building or buying an engine. If you don’t know the reputation and experience level of the company that’s building your engine, you really do not know what you’re getting in the end.