If you’re in the Subaru world, you know the sound of "rod knock" or the pain of a failed engine. When it’s time for a serious overhaul or a major power upgrade, you face a critical choice. A Subaru long block isn't just a replacement part; it's a fresh start—a complete, professionally assembled core for your build. It's the definitive solution for replacing a tired motor or laying the groundwork for a high-performance machine. Instead of piecing an engine together, a long block provides a reliable, powerful foundation. This guide will walk you through everything you need to know before you start your search, from understanding the components to choosing a builder you can trust.
Key Takeaways
- Choose a Long Block for a Cohesive Build: A long block is a nearly complete engine, including the block, internals, and cylinder heads. This pre-assembled unit ensures all core components are professionally matched, which eliminates guesswork and provides a solid foundation for reliable performance.
- Match the Engine to Your Driving Goals: The right long block is one built for your specific purpose, whether it's daily driving, overlanding, or track use. Be sure to also plan for necessary supporting modifications—like an upgraded fuel system, cooling, and a professional tune—to ensure your entire setup can safely handle the increased power.
- Prioritize Build Quality and a Strong Warranty: A long block's cost reflects the quality of its components and the precision of its assembly. A reputable builder will offer a transparent warranty that covers their work, which serves as a direct indicator of their confidence in the engine's performance and durability.
What is a Subaru Long Block?
If you're planning a major engine overhaul or a serious power upgrade for your Subaru, you've likely come across the term "long block." Think of a long block as a nearly complete engine, providing the core foundation for your build. It’s a popular solution for enthusiasts looking to replace a tired or damaged engine with something fresh and reliable, or for those building a high-performance machine from the ground up. Instead of sourcing dozens of individual components, a long block gives you a professionally assembled package ready for your final parts and installation.
What's Inside a Long Block?
A long block is much more than just an empty engine casing. It’s an assembly that includes the most critical internal components. Inside, you'll find the engine block itself, which houses the rotating assembly: the crankshaft, connecting rods, and pistons. Bolted on top are the cylinder heads, which contain the complete valvetrain—camshafts, valves, springs, and lifters. Essentially, it’s the entire engine from the oil pan rail to the valve covers. This pre-assembled unit ensures that the core components work together harmoniously, which is critical for both reliability and performance.
Long Block vs. Short Block: What's the Difference?
The main difference comes down to the cylinder heads. A short block is just the "bottom end" of the engine: the block, crank, rods, and pistons. A long block includes the short block plus the "top end"—the cylinder heads and valvetrain. Choosing a long block means you're getting a fully integrated system where the heads and internal components are professionally matched and assembled. This eliminates the guesswork and potential compatibility issues of building the engine yourself, often leading to better performance and greater peace of mind, especially for high-horsepower applications.
When to Choose a Short Block
Opting for a short block is a path best suited for the experienced engine builder or someone working with a trusted machine shop. A short block is less complete, containing only the engine block and its rotating assembly—the crankshaft, connecting rods, and pistons. This option makes sense if your original cylinder heads are in excellent condition and you have the expertise to properly inspect, machine, and assemble them onto the new bottom end. It allows for more customization of the top-end components but also introduces a higher degree of risk. You're taking on the responsibility for component matching, clearances, and the final assembly, which requires specialized tools and a deep understanding of Subaru engines.
When a Long Block is the Better Option
For most enthusiasts, a long block is the smarter and more reliable choice. A long block is a nearly complete engine that includes the assembled short block plus professionally installed cylinder heads and valvetrain. Choosing this route greatly reduces the risk of assembly errors and saves significant time, as the most critical parts are already expertly matched and put together. This provides a solid, reliable foundation for your build, eliminating the guesswork involved in head-to-block compatibility. Whether you're building a high-horsepower STI for the track or a dependable motor for your daily driver, a long block offers peace of mind and a professionally assembled core ready for your final bolt-on parts.
Does Your Subaru Need a New Long Block?
How do you know it's time for a new long block? Sometimes the signs are obvious and alarming. Loud knocking sounds, often called "rod knock," are a classic indicator of a serious internal failure. Other symptoms can be more subtle, like excessive oil consumption, a significant loss of power, or low compression in one or more cylinders. You might also consider a long block if you're planning a build that will push far beyond the limits of the factory engine. A built long block provides the robust foundation needed to handle aggressive performance parts and a professional tune.
The Best Subaru Long Blocks for Performance
When you’re ready to invest in a new heart for your Subaru, the market offers several excellent options. The right choice depends entirely on your performance goals, driving style, and budget. From custom-built powerhouses designed for the track to reliable factory-spec units, each manufacturer brings something different to the table. Understanding these differences is the first step toward choosing a long block that will not only fit your car but also match your vision for its future performance. Let's look at some of the top contenders in the Subaru performance world.
Crawford Performance: Built for Power
If you have a specific performance goal in mind, a custom-built engine is your best path forward. At Crawford Performance, we specialize in creating Subaru long blocks tailored to your exact needs, whether you're building a track-day monster or a rugged overlanding rig. Each engine is assembled with precision and expertise to ensure it delivers the power and reliability you expect. This bespoke approach means you aren't just buying a part off the shelf; you're investing in a powertrain engineered to suit your unique driving demands for models like the WRX, STI, and Crosstrek.
Technical Specifications and Horsepower
The true advantage of a custom long block lies in the technical details. Unlike a factory replacement, a performance-built engine is constructed with components specifically chosen to handle increased stress and produce more power. This means using high-strength, forged internals—pistons, connecting rods, and a balanced crankshaft—that can withstand higher boost levels and more aggressive tuning. For example, our S-Series long blocks are engineered to support specific horsepower goals, ensuring every component works in harmony. This meticulous assembly is what allows an engine like our EJ257 to reliably produce up to 770 horsepower, providing a solid foundation for serious performance parts and a professional tune.
Two Decades of Subaru Racing Expertise
Our engines aren't just assembled in a workshop; they're born from over 20 years of pushing Subarus to their absolute limits on the racetrack. This extensive racing heritage means we have a deep, practical understanding of what makes these engines perform and where their weaknesses lie. We apply that hard-won knowledge to every long block we build, reinforcing common failure points and optimizing for durability under extreme conditions. This confidence in our engineering is why we back our engines with a unique 12-month/12,000-mile warranty. When you choose a Crawford long block, you're not just buying an engine; you're investing in decades of proven Subaru expertise.
IAG Performance: A Popular Choice
IAG Performance is another well-regarded name in the Subaru community, known for producing a range of long blocks designed for durability and high horsepower. They offer staged builds that cater to different performance levels, from street-friendly setups to extreme race applications. Many enthusiasts choose IAG for their robust solutions, which often include features like closed-deck conversions to handle significant boost. Their pre-configured options provide a clear upgrade path for those looking for proven power packages without getting into the fine details of a fully custom build.
Engine Features and Naming Conventions
Many builders use a straightforward naming system to indicate an engine's power handling capabilities. You’ll often see long blocks labeled with numbers like "550" or "750," which typically correspond to their intended horsepower limit. This system makes it easy to quickly find an engine that aligns with your power goals. However, it's also important to look beyond the number and examine the specific components used, such as forged pistons and rods, upgraded head studs, and case bolts. These internal upgrades are what truly determine an engine's strength and its ability to handle aggressive performance parts and increased boost levels reliably over time.
Customer Perks and Additional Offerings
A long block is a serious investment, and the builder's warranty is a direct reflection of their confidence in the product. A comprehensive warranty provides peace of mind and protects you from potential defects in materials or assembly. At Crawford Performance, we stand behind our decades of racing experience and precision engineering with a 12-month or 12,000-mile limited warranty on our long blocks. This guarantee ensures that your new engine is built to last, whether you're on the street or the track. When choosing a builder, always consider the warranty and support they offer, as it’s a crucial part of your long-term performance journey.
OEM Subaru: The Factory Standard
For drivers who prioritize reliability and want to maintain their vehicle’s original character, an OEM Subaru long block is a solid choice. These are the same complete engine assemblies that come from the factory, ensuring a perfect fit and function for your specific model. An OEM long block is an excellent option if you're overhauling a high-mileage engine or simply need a dependable replacement for your daily driver. While it won't offer the performance gains of an aftermarket build, it guarantees factory-level quality and restores your Subaru to its stock performance specifications.
More Aftermarket Brands to Consider
Beyond the biggest names, several other aftermarket companies build quality Subaru long blocks. Brands like Sunwest Automotive Engine offer options for a wide variety of models, including the STI, WRX, Outback, and Forester. These builders often cater to a broad spectrum of needs and budgets, providing everything from stock-style rebuilds to mild performance upgrades. Exploring these alternatives can be worthwhile if you're looking for a specific price point or a solution for an older or less common Subaru model, giving you more choices to find the perfect fit for your project.
Sunwest Automotive Engine
For those looking for a broad selection, Sunwest Automotive Engine is another builder to consider. They offer an extensive catalog of Subaru long block options, covering a wide array of models from the performance-focused STI and WRX to the versatile Outback, Legacy, and Forester. This variety makes them a notable resource, especially if you're trying to find a specific engine configuration or a replacement for a less common model. Their focus on providing numerous choices allows enthusiasts to browse a large inventory to find a long block that aligns with their particular project needs, whether it's for a performance upgrade or a straightforward replacement.
Retailers like SubiSpeed
You can also find long blocks through large aftermarket retailers like SubiSpeed. These companies act as a marketplace, offering engine solutions for popular models like the Subaru WRX, STI, Forester, and Crosstrek. Sourcing through a retailer can be a convenient option, especially if you're already purchasing other performance parts for your build from the same place. They typically offer long blocks from various established builders, providing a centralized shopping experience. This approach gives you a reliable and complete assembly with professionally matched components, ensuring a solid foundation for your engine rebuild or replacement project.
Will It Fit? Checking Model Compatibility
No matter which builder you choose, verifying compatibility is the most critical step. Before you make a purchase, confirm the engine is correct for your specific Subaru. You’ll need to match the engine size (e.g., 2.5L or 2.0L), confirm whether it’s for a turbocharged or naturally aspirated model, and ensure it fits your vehicle's year range. An engine for a 2015+ WRX won't work in an older STI. Double-checking these details on pages for Subaru WRX upgrades or your specific model will prevent major headaches and ensure a smooth installation process.
Common Subaru Engine Codes: EJ25 vs. FA20
As you explore long block options, you'll encounter two primary engine codes: the EJ25 and the FA20. The EJ25 is a legendary platform, powering models like the 2002–2014 WRX and the 2004–2021 STI. It's known for its raw, analog feel and has a massive aftermarket following, making it a go-to for enthusiasts chasing big power figures. In contrast, the FA20 DIT (Direct Injection Turbo) is the more modern engine found in the 2015–2021 WRX. It introduced direct injection technology to the platform, offering a different power delivery and tuning experience. Knowing which engine your car is equipped with is fundamental, as it dictates everything from component compatibility to your overall upgrade strategy. Each engine has unique strengths, and choosing the right long block ensures your build starts on a solid, compatible foundation.
How Much Does a Subaru Long Block Cost?
Investing in a new long block is a major step, and the price can vary significantly based on your performance goals. The cost reflects not just the individual components, but the expert assembly, machining, and testing that go into creating a reliable, high-output engine. Think of it as the heart of your build—getting it right is the foundation for everything else.
Price Ranges by Performance Level
For a high-quality aftermarket Subaru long block, you can generally expect the price to fall between $6,999 and $19,500. The lower end of this range typically covers durable engines suitable for spirited daily driving or moderate track use, often built to handle more power than a stock motor. As you move up in price, you’re paying for more extensive modifications, higher-grade materials, and components engineered for serious competition. For example, a top-tier build like the Ken Block Spec EJ257 engine sits around the $12,000 mark, reflecting its capacity for extreme performance and reliability under pressure.
Comparing Vendor Pricing
As you compare long blocks, you'll see a wide range of prices. This cost difference directly reflects the quality of the internal components, the precision of the assembly, and the engine's ultimate performance capabilities. For a custom-built engine from Crawford Performance, our standard options range from $3,195 to $6,295, offering a tailored foundation for your specific build. In comparison, vendors like IAG Performance provide staged builds that start around $8,925 and can exceed $15,900 for their highest-tier options. Sunwest Automotive Engine offers long blocks from $10,000 to $19,500, while a factory-spec OEM Subaru long block typically costs between $6,999 and $12,000. Understanding these price points is key to matching your budget with your performance goals.
What Affects the Final Price?
The final price of a long block is determined by more than just a list of parts. You're investing in a fully integrated system. A key benefit of a long block is that the cylinder heads, camshafts, and valvetrain are all selected and assembled to work in perfect harmony. This synergy is crucial for maximizing power and ensuring longevity. Attempting to pair a new short block with old, worn cylinder heads can create compatibility issues and lead to premature failure. The higher cost of a complete long block accounts for the precision machining and assembly that prevent these problems, giving you a cohesive unit built for performance from the start.
Cost Differences Between Engine Types
The specific engine in your Subaru plays a big role in the cost of a long block. For instance, the price for an EJ-series engine found in an older Subaru STI will differ from the FA-series engine in a newer WRX. This is due to variations in component design, availability, and the specific performance upgrades each platform requires. A long block built for extreme horsepower will naturally cost more than one designed for a reliable daily driver, as it will include forged internals and other high-strength components. The key is to match the engine's capabilities—and its price tag—to your actual driving needs, ensuring you're not overpaying for performance you won't use or under-building for your goals.
Factoring in Installation Kits
The price of the long block itself is just the starting point. To ensure a smooth and reliable installation, you'll also need to budget for an installation kit. These kits are crucial and typically include essential items like a new timing belt or chain, tensioners, gaskets, seals, and all the necessary fluids. Some builders offer these as add-on packages. Skipping these components is a risky shortcut; reusing old parts with a brand-new engine can lead to leaks or premature failure. Think of it as part of the total investment in your vehicle's new heart. A complete kit ensures your new long block integrates seamlessly with the rest of your car, protecting your investment and giving you peace of mind on the road or track.
How Performance Upgrades Affect the Cost
To reliably make big power, your engine needs a strong foundation. While engine tuning can unlock significant gains, the stock internals can only handle so much before they become a weak point. That's why performance long blocks include fundamental upgrades like forged pistons and stronger connecting rods. These components are essential for withstanding the increased stress from higher boost and more aggressive timing. While these upgrades add to the initial cost, they are a critical investment for anyone planning to install larger turbos or other major performance parts. Building the engine to handle your power goals from the outset is the smartest way to ensure your Subaru runs strong for years to come.
What to Look for in a Long Block Warranty
A new long block is a major investment in your Subaru's future, and a solid warranty is your safety net. But not all warranties are created equal. The fine print can be the difference between a quick, covered repair and a massive, unexpected bill. Before you commit, it’s critical to understand exactly what protection you’re getting. A warranty isn't just a document; it's a manufacturer's promise that they stand behind their work, especially when you're pushing your car on the track or trail. This is particularly true for performance engines, which operate under far greater stress than a stock motor. The warranty tells you how much confidence the builder has in their components and assembly process.
Think of it this way: you wouldn't buy a house without inspecting the foundation, and you shouldn't buy an engine without scrutinizing the warranty. Look for clear language, comprehensive coverage for critical components, and a term that reflects the engine's intended use. A vague or restrictive warranty can be a red flag, signaling a lack of confidence in the product. A transparent, robust warranty shows that the builder is proud of their craftsmanship and is ready to support you if something goes wrong with your Subaru WRX upgrades or other model enhancements. It provides peace of mind, allowing you to fully enjoy the power and reliability you've invested in.
What's Actually Covered (and What's Not)
When you read through a long block warranty, the first thing to check is which parts are actually included. Most warranties will cover the core of the engine: the engine block itself, cylinder heads, and the internal rotating assembly (pistons, rods, crankshaft). This is the heart of your motor, and it’s where the most catastrophic failures can occur.
However, it's just as important to know what isn't covered. Typically, external components and accessories are excluded. This means parts like the intake and exhaust manifolds, turbocharger, fuel injectors, and sensors are your responsibility. Make sure you understand this distinction, as a failure of an uncovered external part could potentially damage the covered long block, creating a complicated warranty claim.
Reading the Fine Print: Duration and Limitations
The length of a warranty, usually stated in months and miles (e.g., 12 months or 12,000 miles), is a key indicator of the manufacturer's confidence. While a factory car might come with a five-year powertrain warranty, high-performance engines operate under much greater stress, so their warranty terms are different.
Beyond the duration, pay close attention to the limitations and potential voids. Will a custom tune void your coverage? What about track days or competitive events? Reputable builders are clear about these conditions. Improper installation, failure to follow break-in procedures, or using the wrong fluids are common reasons for a denied claim. A good warranty will have straightforward terms that protect both you and the builder.
The Crawford Performance Warranty Advantage
At Crawford Performance, we build engines for enthusiasts who intend to use them. That’s why we back our S-Series long blocks with a comprehensive 12-month/12,000-mile warranty. This isn't a standard factory warranty adapted for performance use; it's designed from the ground up for our built engines. We cover the essential internal components against defects in materials and workmanship, giving you the confidence to enjoy the power you paid for.
Our warranty reflects decades of engineering and track-tested validation. We know what our engines can handle because we’ve pushed them to the limit ourselves. By using premium performance parts and adhering to meticulous assembly standards, we provide a warranty that serves as a genuine promise of quality and reliability for your high-performance Subaru.
How to Choose the Right Long Block for Your Subaru
Selecting a new long block is a major upgrade for your Subaru. As the heart of your build, getting it right is key to achieving your performance goals. The best choice isn't just about raw power; it's about finding an engine that aligns with your vehicle, driving style, and budget. To make a confident decision, you need to think through a few key areas: your performance goals, the supporting modifications you'll need, and the overall build quality. Let's walk through each of these steps to find the right fit for you.
Match Your Engine and Performance Goals
Before you look at a single spec sheet, define your car's purpose. A daily driver has very different needs than a dedicated track build. Are you building an overlanding rig for rugged trails or a weekend warrior for the drag strip? Each goal demands a different balance of power and reliability. A 400-horsepower street car requires a different internal setup than a 600-horsepower race engine. Being realistic about your power targets and driving habits helps you invest in an engine that will perform reliably. This clarity ensures you get the right Subaru WRX upgrades for your specific application.
The Long-Term Value of a Performance Build
Investing in a performance long block is about more than just chasing a horsepower number; it’s about building a reliable foundation for your car's future. When you choose a professionally assembled long block, you get a cohesive system where every internal component is selected to work in harmony. This approach eliminates the risks and guesswork that come with piecing an engine together yourself. A well-built engine provides a solid base that can handle the increased stress from future performance parts, like a larger turbo or an aggressive tune, ensuring your entire setup is stable and dependable for years to come.
The price of a quality long block reflects the expertise and premium components inside. You're paying for precision machining, meticulous assembly, and the confidence that comes from an engine built to last. A reputable builder will always back their work with a transparent warranty, which is a direct reflection of their confidence in the engine's durability. This warranty isn't just a piece of paper; it's your assurance that the investment is protected. Ultimately, a performance build adds significant long-term value, giving you a powerful and reliable Subaru you can enjoy without constantly worrying about what’s under the hood.
What Other Modifications Will You Need?
A high-performance long block doesn't work alone. To reliably handle more power, your engine needs a team of supporting players. While the long block may include fundamental upgrades like forged pistons, you also have to consider external systems. Your fuel injectors, fuel pump, turbo, and cooling system must all be up to the task. Without the right supporting mods, you risk the health of your new engine. A professional tune is also critical to make sure all your new components work together in harmony. Factor these additional performance parts into your budget from the start.
Assess Build Quality and Installation Requirements
The quality of the assembly is just as important as the parts inside. Choosing a long block from a reputable builder means you're getting an integrated system where the cylinder heads, camshafts, and valvetrain are perfectly matched and assembled to precise specifications. This attention to detail is what creates a reliable engine. This pre-assembly also simplifies the installation process, as the most complex work is already done, making an engine swap much faster. When comparing builders, look for transparency in their process, positive reviews, and a solid warranty to back up their work.
Getting a Detailed Parts List
When you're comparing long blocks, a detailed parts list is your best friend. A reputable builder will always provide a complete breakdown of every component used in the assembly, from the brand of the pistons and connecting rods to the specifics of the camshafts and valve springs. This transparency is a huge indicator of quality. It shows the builder is confident in their choices and allows you to see exactly what you’re paying for. A comprehensive list helps you compare different builds on an apples-to-apples basis and ensures you’re getting the right performance parts for your power goals. Don't hesitate to ask for this list; it’s a critical piece of information for making an informed investment in your Subaru's new engine.
Post-Installation: The Crucial Break-In Period
Once your new long block is installed, the temptation to immediately test its limits is strong. But the first few weeks of driving are the most critical for your engine's long-term health and performance. This is the break-in period, a vital process where the new internal components settle into place. Specifically, it allows the piston rings to properly seat against the cylinder walls, creating a tight seal that is essential for optimal compression, power, and oil control. Rushing this process can lead to permanent issues like excessive oil consumption and reduced performance down the road. Think of it as the final, careful step of the build process—one that you are in complete control of.
Properly breaking in your engine ensures that all the precision-machined surfaces wear in together smoothly, maximizing both power and longevity. Following the builder's recommended procedure is not just a suggestion; it's a requirement for protecting your investment and is often a condition of your warranty. For the first 1,000 to 1,500 miles, your driving habits will directly influence how well the engine performs for years to come. This period also requires a professional tune to ensure the engine is running safely with all its new components. A proper engine tuning service will calibrate the system for the new hardware, which is just as important as the mechanical break-in itself.
Essential Break-In Procedures
Following a specific break-in procedure is non-negotiable. For the first 1,000-1,500 miles, your main goal is to drive gently while varying the engine's speed. This means avoiding long highway trips on cruise control and instead opting for routes that allow you to naturally change RPMs. You should keep the engine out of high boost and avoid full-throttle acceleration. It’s also important to let the engine warm up completely before driving and to perform an oil change right after the break-in period is complete to flush out any initial metal particles from the new components. Adhering to these steps ensures your warranty remains intact and gives your new engine the best possible start for a long and powerful life in your Subaru Crosstrek or performance model.
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Frequently Asked Questions
Why should I choose a long block instead of just buying a short block and reusing my old cylinder heads? While reusing your cylinder heads might seem like a way to save money, it can introduce serious risks. Your old heads may have wear, warping, or compatibility issues that can compromise the integrity of your new short block, potentially leading to premature failure. A long block is a fully integrated and professionally assembled unit where the heads, valvetrain, and bottom end are all matched and tested to work together perfectly. This ensures proper clearances and synergy between all components, giving you a more reliable foundation for performance.
What other parts should I budget for when buying a new long block? A new long block is the core of your build, but it needs a strong supporting cast. You should plan for a new clutch, as the engine will need to be removed for the installation anyway. It's also wise to budget for a new water pump, thermostat, and oil cooler. Depending on your power goals, you will likely need to upgrade your fuel pump, injectors, and turbocharger to supply the engine with what it needs to perform safely and effectively.
Will a professional tune void the warranty on my new long block? On the contrary, a professional tune is almost always a requirement to validate the warranty. Performance long blocks are built with specific components that require precise calibration to function correctly. Running a built engine on a stock or off-the-shelf tune can cause damage and will typically void your coverage. Reputable builders expect you to get a professional tune to ensure the engine operates safely within its new parameters, protecting your investment.
Is a more expensive long block always the right choice for my build? Not necessarily. The best long block is the one that aligns with your specific performance goals and how you plan to use your car. A top-tier engine built for 700 horsepower is overkill for a daily driver or a light-duty overlanding rig. It's more important to choose an engine built with quality components that can reliably handle your target power level. Investing in a long block that matches your goals is a smarter use of your budget than simply buying the most expensive option available.
How important is the engine break-in period for a new long block? The break-in period is absolutely critical. This process allows the new piston rings to seat properly against the cylinder walls, ensures all new components settle in together, and helps flush out any initial assembly lubricants or microscopic debris. Failing to follow the manufacturer's specific break-in procedure—which usually involves varying engine speeds and avoiding high loads—is one of the fastest ways to damage your new engine and void your warranty.