Your stock FA20 engine is a solid foundation, but it wasn't designed for skyscraper-level power. Pushing it hard with a bigger turbo or an aggressive E85 tune can feel like a gamble. You need a stronger base to build upon. A performance FA20 long block is that reinforced foundation. It provides the internal strength required to safely support every modification you add, giving you peace of mind. We'll break down how that foundation is built, which components matter most, and how to ensure your setup is balanced for reliable power.
Key Takeaways
- A Built Engine is Your Foundation for Safe Power: Upgrading to a performance long block isn't just about chasing high horsepower; it's about creating a durable foundation with forged internals that can reliably handle the stress of aggressive modifications and driving.
- Your Engine's Success Depends on the Builder: The quality of your long block is determined by the skill of the person assembling it. Choose a dedicated Subaru specialist with a transparent process, a strong warranty, and a proven reputation to protect your investment.
- Plan for a Complete System, Not Just an Engine: A built long block requires supporting modifications to function correctly. You must budget for essential upgrades like a larger turbo, a robust fuel system, improved cooling, and a professional tune to ensure reliable performance.
What is an FA20 Long Block?
If you're planning a serious engine build for your Subaru, you've likely come across the term "long block." Think of it as a nearly complete engine package. A long block includes the entire short block (the bottom half of the engine) plus the top half, which consists of the cylinder heads, camshafts, and valvetrain. Essentially, it’s the heart of your engine, assembled and ready for the final components like the intake manifold, turbo, and accessories to be bolted on.
For enthusiasts looking to make significant power gains or replace a damaged engine, a pre-assembled long block is an excellent solution. It saves you the complex and time-consuming task of sourcing individual parts and assembling the engine's core components yourself. This approach ensures that critical tolerances are set correctly by experienced builders, giving you a solid foundation for a reliable, high-performance setup. Whether you're building a track-ready Subaru WRX or a powerful daily driver, starting with a quality long block is one of the smartest moves you can make.
Which Subaru Models Use the FA20 Engine?
The FA20 engine isn't a one-size-fits-all power plant. Subaru developed two distinct versions to suit different driving styles and vehicle platforms. The main difference comes down to aspiration: one is turbocharged for forced-induction power, while the other is naturally aspirated, prioritizing response and balance. Knowing which version your car has is the first step in planning your build, as it dictates your modification path and performance potential. Each variant has its own strengths and a dedicated community of enthusiasts pushing its limits.
The Turbocharged FA20F in the WRX and Forester XT
If you're driving a 2015-2021 Subaru WRX or a 2014-2018 Forester XT, you have the turbocharged FA20F engine. This direct-injected motor was designed from the ground up to handle boost, making it a fantastic platform for performance tuning. The turbo provides that signature surge of power that drivers love, offering impressive torque right from the factory. For enthusiasts, the FA20F is a playground for modifications, responding exceptionally well to upgrades like better breathing components, fuel system enhancements, and custom tunes. It's the engine that provides the modern WRX with its rally-bred character and gives the Forester XT a surprising punch.
The Naturally Aspirated FA20D in the BRZ, FR-S, and 86
The FA20D is the heart of the lightweight sports coupe platform, found in the 2012–2020 Subaru BRZ, Scion FR-S, and Toyota 86. This naturally aspirated version is all about driver engagement. It features a high-revving design and a combination of direct and port injection, delivering crisp throttle response and a linear powerband. While it doesn't have the out-of-the-box torque of its turbocharged sibling, its focus is on creating a balanced and nimble driving experience. For many owners, the FA20D is the perfect match for the chassis, but its strong internals also make it a popular candidate for aftermarket supercharger and turbo kits, allowing you to add serious power while maintaining the car's agile feel with the right performance parts.
What's Inside a Performance Long Block?
Not all long blocks are created equal. A performance long block is specifically engineered to handle much more power and abuse than a stock engine. To achieve this reliably, the engine needs fundamental upgrades like forged pistons and stronger connecting rods. These core performance parts are essential for managing the increased cylinder pressures that come with higher horsepower.
Beyond the pistons and rods, a built long block often includes upgraded bearings, ARP head studs for superior clamping force, and sometimes performance camshafts and valvetrain components. Every part is chosen to work in harmony, creating a durable package that can withstand the demands of aggressive driving, whether on the street or the track.
Long Block vs. Short Block: What's the Difference?
The main distinction is completeness. A short block is just the bottom part of the engine—the engine block, crankshaft, connecting rods, and pistons. A long block includes all of that, plus the cylinder heads and valvetrain, already put together.
Choosing between them depends on your project's needs. If your cylinder heads are in great shape and you're comfortable having a machine shop prepare them, a short block might be sufficient. However, a long block offers a more integrated solution. It eliminates the guesswork of matching components and ensures the entire assembly is built to the same high standard, making it a more direct path to getting your car back on the road with a powerful and reliable engine.
Why Upgrade to a Performance FA20 Long Block?
Deciding to upgrade to a performance FA20 long block is a major step for any Subaru owner. It’s not just about replacing a worn-out engine; it’s about laying a new foundation for power, reliability, and peace of mind. The stock FA20 engine is great for daily driving, but it has its limits, especially when you start adding modifications to increase horsepower. Pushing the stock internals too far can lead to catastrophic failure, turning your dream build into a nightmare.
A performance-built long block addresses these limitations from the inside out. It’s a comprehensive solution that replaces the factory’s mass-produced components with high-strength, precision-engineered parts designed to handle significant stress. This upgrade is essential for anyone serious about track days, competitive racing, or even demanding overlanding solutions where engine dependability is critical. By strengthening the engine’s core, you create a platform that can safely support a larger turbo, a more aggressive tune, and the demands of spirited driving, all while giving you the confidence that your engine is built to last.
Gain Serious Durability and Reliability
A performance-built FA20 long block isn't just a replacement; it's a complete re-engineering of the engine's core. It swaps out weak points for stronger, more reliable components. The goal is to create an engine that can withstand far more abuse than the original factory unit. This process involves meticulous assembly with parts made from superior materials that can handle higher temperatures and pressures. For you, this means a more robust engine that’s less prone to the common failure points seen in modified stock blocks. This added durability provides peace of mind, whether you’re on a long road trip or pushing your car on a closed course.
Prevent Common Failures Like Rod Knock
One of the biggest fears for any modified Subaru owner is the dreaded sound of rod knock. This catastrophic failure often happens when the stock engine's connecting rods, which were never designed for high horsepower, give out under the stress of increased boost and power. A performance long block directly addresses this vulnerability by replacing those factory parts with robust, forged internals. These high-strength components are engineered to handle immense pressure, giving you a solid foundation to build upon. It’s an investment in your car's strength and dependability, ensuring your engine can reliably manage the power you want to make without self-destructing.
Reduce Excessive Oil Consumption
Excessive oil consumption can be a persistent issue with stock FA20 engines, especially when they are pushed hard. A professionally built long block helps solve this problem through superior components and meticulous assembly. Upgraded pistons and piston rings create a much better seal within the cylinder, which significantly reduces oil blow-by. When combined with the careful assembly process from an experienced engine builder, you get an engine that manages oil far more effectively. This not only keeps your engine healthier but also ensures its performance remains consistent. A professional engine tune is essential to finalize the setup, optimizing all parameters for a healthy, reliable system.
Safely Handle More Power
If your goal is to make significantly more power than stock, a built long block is non-negotiable. To achieve this reliably, the engine needs fundamental upgrades like forged pistons and stronger connecting rods. These core performance parts allow the engine to handle higher cylinder pressures and more aggressive driving without failure. The stock components in your Subaru WRX or BRZ were simply not designed for the stress that comes with a larger turbo or an aggressive E85 tune. A performance long block provides the internal strength necessary to support these modifications, letting you safely push for higher horsepower and torque figures.
Keep Your Engine Cool Under Pressure
More power generates more heat, and managing that heat is crucial for engine longevity and consistent performance. A forged FA20 long block is the go-to foundation for anyone planning to add a larger turbo, run higher boost, or push their car on the track. These upgrades often necessitate improved cooling systems to maintain optimal engine temperatures. Many performance long blocks are designed with enhanced cooling properties, using materials and designs that dissipate heat more effectively. This helps prevent overheating during intense driving sessions, protecting your investment and ensuring your engine delivers reliable power lap after lap.
Benefit from a "Drop-In" Ready Installation
One of the biggest perks of choosing a pre-assembled long block is how much it simplifies the installation. Building an engine from scratch is a massive undertaking that requires specialized tools, a perfectly clean space, and a ton of expertise. A performance long block, however, arrives fully assembled, timed, and ready to be installed. This "drop-in" solution drastically cuts down on the complexity and the time your car is out of commission. Instead of weeks spent on a meticulous build, the installation can often be done in a fraction of the time, which saves you on labor costs and gets you back behind the wheel faster. It also eliminates the risk of assembly errors, giving you confidence that all internal performance parts are set to exact specifications by a professional.
Built FA20 vs. Other Engine Swaps
While the idea of swapping in a completely different engine might sound exciting, it often opens a Pandora's box of complications and hidden expenses. A built FA20 long block isn't just a replacement; it's a complete re-engineering for strength and reliability designed to integrate perfectly with your Subaru's existing systems. Engine swaps, in contrast, usually demand custom mounts, complex wiring solutions, and significant fabrication to make everything work together. These hurdles can quickly turn your project into a frustrating and costly nightmare. Sticking with a built FA20 keeps the process direct, preserving your car's integrity while delivering a huge upgrade in power and durability without the headaches of a cross-platform swap.
How Much Does an FA20 Long Block Cost?
When you’re ready to build a Subaru capable of serious performance, the engine is the heart of the project. Investing in a built FA20 long block is a significant step, and understanding the costs involved is key to planning a successful build. The price isn't just for a part; it's for a completely re-engineered foundation designed for power and durability far beyond stock capabilities.
The total cost depends on the components you choose, the builder’s expertise, and the supporting modifications required to make it all work together. Let's break down the numbers so you can create a realistic budget for your goals.
Understanding the Cost Breakdown
A professionally built, high-performance FA20 long block can range from $9,000 to over $19,000. This wide range reflects the quality of the internal components and the extent of the machine work. A basic build might use quality forged pistons and rods, while a top-tier engine will include CNC-ported cylinder heads, upgraded valvetrain components, and other precision modifications designed for maximum airflow and strength. The final price tag is a direct reflection of the engine's power-handling capabilities and overall durability. It’s an investment in a reliable foundation that can handle whatever you throw at it.
Factoring in Core Charges
When you're budgeting for your long block, you'll notice an item called a "core charge." Think of this as a refundable deposit for your old engine. Builders need a steady supply of usable engine blocks, or "cores," to rebuild for future customers. The core charge ensures they get your old engine back in a rebuildable condition. For example, a core deposit can be around $3,000. Once you ship your original engine back to the builder and they inspect it to confirm it’s in good shape, that deposit is returned to you. It’s a standard practice in the industry that helps keep the cycle of high-performance engine building going.
Deposits, Final Payments, and Build Times
The process typically begins with a deposit to secure your spot in the builder's queue. Once your engine is complete, you'll need to cover the final payment before it ships. This final invoice will include the remaining balance for the long block, shipping costs, the core deposit, and any applicable sales tax. It's also important to set realistic expectations for the timeline. A custom-built performance engine isn't an off-the-shelf part; it's assembled with precision and care. A long waitlist is often a sign of a reputable builder whose work is in high demand. This commitment to quality is why top builders provide a solid engine warranty, giving you confidence that your investment is protected.
What Determines the Final Price?
A performance-built FA20 long block is much more than a factory replacement; it’s a ground-up re-engineering of the engine’s core. The process involves disassembling the engine, inspecting every component, and replacing weak points with stronger, more reliable parts. The primary cost drivers are the forged internals—pistons, connecting rods, and crankshaft—as well as the labor-intensive machine work and assembly by experienced technicians. For comparison, a performance short block can be a more budget-friendly starting point, but a long block provides a complete, ready-to-install solution with fully prepared cylinder heads, saving you time and potential compatibility issues.
Short Block Pricing for Comparison
While a performance long block can range from $9,000 to over $19,000, a performance short block offers a more budget-friendly starting point. However, it's crucial to understand what that lower price entails. A short block is only the bottom half of the engine, meaning you are still responsible for sourcing, machining, and assembling the cylinder heads and valvetrain. This adds complexity and introduces the risk of mismatched components or assembly errors. Investing in a long block provides a more integrated solution, where the entire engine is built to a single high standard by one builder. This ensures all parts work together perfectly, giving you a more reliable foundation for your high-horsepower goals and a more direct path to getting back on the road.
How to Budget for Essential Supporting Mods
The long block itself is just one part of the equation. To safely handle the increased power, you must budget for several essential supporting modifications. Your stock fuel system and turbocharger won't keep up, so you'll need to upgrade to a larger turbo, higher-flow injectors, and a more robust fuel pump. Improved cooling is also non-negotiable, meaning a better radiator and an external oil cooler are necessary to manage heat. Finally, you must factor in the cost of an Air-Oil Separator (AOS) to protect your investment from oil contamination, plus shipping, professional installation, and a custom engine tune to dial everything in perfectly.
How to Choose an FA20 Long Block Builder
Choosing a builder for your FA20 long block is the single most important decision you'll make in this process. You can have a pallet of the best performance parts on the market, but without the right hands assembling them, you're setting yourself up for failure. The builder is more than just an assembler; they are an engineer, a machinist, and a Subaru expert all in one. Their experience, attention to detail, and processes determine whether your engine will be a reliable powerhouse or a constant headache.
When you invest in a built long block, you're paying for that expertise just as much as the physical components. A great builder understands the unique quirks of the FA20 platform, from its oiling system to its cooling needs. They know which components work well together and how to machine and tolerance everything for maximum durability under pressure. Before you commit to a builder, it’s essential to do your homework. Vetting their specialization, parts selection, warranty, and reputation will ensure your investment is protected and your performance goals are met. The right choice here makes all the difference between achieving your dream build and facing a costly nightmare.
Why You Need a True Subaru Specialist
When you’re looking for a builder, don't settle for a general engine shop. You need a true Subaru specialist. The FA20 is a unique engine with specific weaknesses and strengths that only an experienced Subaru builder will fully understand. A specialist has spent years, if not decades, working exclusively on these platforms. They’ve seen what fails, what works, and what it takes to build an engine that can handle serious power reliably. They have the specialized tools and knowledge required for precision work, from decking the block to balancing the rotating assembly. Ask potential builders about their direct experience with FA20s and their approach to expert tuning services post-installation. Their answers will quickly reveal their level of expertise.
What to Look for in Their Parts List
A performance-built FA20 long block is a complete re-engineering of the engine's core, not just a simple replacement. It involves strategically swapping out weaker factory components for stronger, more durable aftermarket parts. Any reputable builder should provide a detailed, transparent list of every single component used in their build. Scrutinize this list carefully. Does it include high-quality forged pistons, rods, and a crankshaft? Are they using proven brands for bearings and head studs? A builder who is confident in their work will be proud to show you the exact performance parts they use. If a builder is vague about their parts list or uses generic descriptions, consider it a major red flag.
Examples of High-Quality Component Brands
When you review a builder's parts list, you should see names that are well-respected in the Subaru community. Companies like IAG Performance are known for their meticulously hand-built engines, while Manley Performance is a go-to source for high-strength pistons and connecting rods. Here at Crawford Performance, we have a long history of developing and testing our own performance parts to ensure they meet the highest standards for reliability and power. A reputable builder will always use components from trusted manufacturers because they know that the engine's strength is only as good as its weakest link. Seeing these brands on a build sheet is a strong indicator that the builder prioritizes quality and isn't cutting corners to save a few dollars.
Standard vs. Upgraded Part Options
The fundamental difference between a stock FA20 and a performance-built long block comes down to the materials and construction of its core components. Your factory engine uses cast pistons and connecting rods, which are perfectly adequate for daily driving but become a critical failure point under the stress of added horsepower. In contrast, a performance long block features forged pistons and stronger connecting rods. Forging creates a much denser and stronger part, allowing it to withstand the intense heat and cylinder pressures that come with a bigger turbo and an aggressive tune. This upgrade is the bare minimum for any serious build, providing the durable foundation needed for reliable power.
Verify the Warranty and Support
A warranty is more than just a piece of paper; it’s a direct reflection of the builder's confidence in their product. A solid warranty, like a 12-month/12,000-mile policy, shows that the builder stands behind their craftsmanship and the quality of the parts they use. Be sure to read the fine print. Most warranties require the engine to be installed and tuned by a certified professional to remain valid, which is a reasonable expectation to protect both you and the builder. Also, consider the support offered after the sale. Will they be available to answer questions your installer might have? A builder who offers strong post-purchase support is invested in your success.
Investigate Their Reputation and Reviews
A builder’s reputation is earned over years of successful builds and satisfied customers. Before making a decision, do some digging. Look beyond the testimonials on their website and search for independent reviews on forums, social media groups, and Google. See what real customers are saying about their experience, the engine's performance, and the company's customer service. A reputable builder will have a consistent history of positive feedback and a track record of resolving any issues that arise. Pay attention to how they interact with the community and respond to criticism. A strong reputation in the Subaru world is hard-earned and is often the best indicator of quality and reliability.
Custom Builds vs. Pre-Configured Packages
When upgrading your engine, you'll face a key decision: go with a custom build or a pre-configured package? A pre-configured package, like a performance long block, is a fully assembled engine core built by experts. This approach saves you the complex task of sourcing individual parts and ensures critical tolerances are set correctly, giving you a solid foundation for reliable power. A custom build, on the other hand, is a ground-up project where you or your chosen shop select every single component. This path offers ultimate personalization but requires a deep understanding of how all the performance parts work together. For most enthusiasts seeking a straightforward path to significant and reliable power gains, a pre-configured package is the ideal solution.
Who Builds the Best FA20 Long Blocks?
Choosing an engine builder is one of the most critical decisions you'll make for your Subaru. It’s not just about buying a product; it’s about trusting a team with the heart of your vehicle. The right builder brings a combination of deep expertise, quality components, and a proven process to the table. The wrong one can leave you with a costly, unreliable engine and a lot of frustration. When you start your search, you’ll find many shops offering built FA20s, but their quality and engineering philosophies can vary dramatically.
A performance-built FA20 long block is a significant investment, so it’s essential to do your homework. You’re looking for a partner who understands the nuances of the Subaru platform and has a track record of building powerful, durable engines. This means looking beyond flashy horsepower numbers and marketing claims. You need to examine their build process, the specific parts they use, their testing procedures, and the support they offer after the sale. A great builder is transparent, stands behind their work with a solid warranty, and has a long list of satisfied customers who can vouch for their reliability. This isn't a component you want to compromise on, as the engine's integrity affects every other performance modification you make.
Why Choose a Crawford Performance Long Block?
When you want a serious performance upgrade without the complexities of a full engine swap, the Crawford FA20 engine is engineered to deliver. We design our long blocks for a direct fit into your Subaru, giving you a straightforward path to more power and reliability. Our philosophy centers on creating engines built for longevity, not just a few impressive dyno pulls. We focus on durability for the demands of both daily driving and aggressive track use. This commitment means every component is selected and assembled to create a balanced, robust engine that you can depend on. Our deep experience with Subaru platforms ensures your build is founded on proven performance parts and assembly techniques.
How Other Builders Stack Up
The FA20 is a popular platform for performance builds, partly because it has fewer widespread reliability issues than its predecessors. As you look at different builders, you’ll notice a wide range of prices and promises. It’s important to remember that a performance-built long block is a complete re-engineering of the engine’s core, not just a simple replacement. Some builders may use lower-quality components or skip critical steps to offer a lower price. When comparing your options for Subaru WRX upgrades, look closely at the parts list, the machining processes, and the builder’s reputation within the community. A cheaper engine often ends up costing more in the long run.
What Defines a Quality Engine Builder?
A reputable engine builder will always be transparent about their process and the parts they use. Look for a shop that specializes in Subarus—their focused expertise is invaluable. They should have a proven track record and be willing to share details about their builds. A key indicator of quality is their use of fundamental upgrades like forged pistons and stronger connecting rods, which are essential for any serious build. Finally, always ask about the warranty. A builder who is confident in their work will offer a comprehensive warranty and clear support, much like our engine tuning services are backed by years of specialized knowledge.
How Much Power Can a Built FA20 Handle?
One of the most common questions we get is about the power potential of the FA20 engine. While the stock engine is impressive, pushing it too far without the right upgrades can lead to catastrophic failure. A professionally built long block, on the other hand, completely changes the game. It provides the strong foundation you need to add serious power without sacrificing reliability. The key is to understand the limits of your stock components and build a setup that aligns with your performance goals and driving habits.
Know the Limits of Your Stock Engine
The stock FA20 engine is engineered for daily driving and can handle minor upgrades quite well. However, it has a ceiling. You can reliably push a stock block to about 350–400 horsepower, but going beyond that is asking for trouble. The factory pistons and connecting rods are the primary weak points and simply aren't designed to withstand the increased stress from higher boost levels or aggressive track use. If your goals include 500, 600, or even 700 horsepower, a built engine isn't just an option—it's a necessity to prevent critical parts from breaking.
How to Set Realistic Power Goals
So, what can a built engine actually handle? A performance-built FA20 long block can reliably manage over 600 horsepower, but it's crucial to remember that the engine is just one piece of the puzzle. Reaching that number safely requires the right supporting modifications and professional engine tuning services. A larger turbo, an upgraded fuel system, and improved cooling are all essential components that work together with your built block. Setting a realistic power goal from the start helps you create a balanced build where every part is chosen to support the others, ensuring you get the performance you want without compromising dependability.
Align Your Build with Your Driving Style
Your ideal build depends entirely on how you plan to use your car. A daily driver that sees occasional spirited driving has different needs than a dedicated track car. To reliably handle higher power levels, your engine needs fundamental upgrades like forged pistons and stronger connecting rods. These core performance parts are essential for anyone planning to add a larger turbo, run higher boost, or consistently push their car to its limits. By aligning your build with your driving style, you ensure every component is up to the task, giving you confidence every time you get behind the wheel.
Which Performance Parts Matter Most?
When you decide to build an FA20 long block, you’re investing in a foundation for serious power. But not all builds are created equal. The real strength of a performance engine comes from a carefully selected combination of components designed to work together. While every part plays a role, a few key upgrades make the biggest difference in creating a durable engine that can handle the demands of the track, trail, or street. These are the non-negotiable upgrades that separate a reliable high-horsepower build from one that’s destined for failure. Focusing on these core areas ensures your investment is sound and your engine is ready for whatever you throw at it.
Why Forged Internals are a Must
The stock FA20 engine is great for daily driving, but its internal components—specifically the pistons and connecting rods—are known weak points when you start adding significant power. To achieve your goals reliably, the engine needs fundamental upgrades like forged pistons and stronger connecting rods. These core performance parts are essential for handling increased cylinder pressures and preventing common failures. Forging creates a much denser and stronger component than the stock cast parts, giving your engine the resilience it needs to manage higher boost levels and aggressive tuning without compromise.
Why Cylinder Head Work is Crucial
Power isn't just about withstanding pressure; it's also about efficient airflow. A performance-built FA20 long block isn't just a replacement; it's a complete re-engineering of the engine's core. It swaps out weak points for stronger components, including upgraded cylinder heads that improve airflow and performance. Professional cylinder head work, like porting and polishing, smooths out the pathways for air and fuel to enter and exit the combustion chamber. This allows your engine to "breathe" better, which is critical for making more power, especially when paired with a larger turbo.
The Importance of Compression Ratios
Think of the compression ratio as how tightly the engine squeezes the air and fuel mixture in the cylinder right before it ignites. Getting this ratio right is a delicate balancing act in any performance build. While a higher ratio can give you snappier throttle response and better efficiency, it also raises the risk of engine knock—a major concern for a turbocharged engine like the FA20. The pistons you select are the main component that sets this ratio, so your choice has to be in sync with your turbo size and the type of fuel you plan to run. For example, a build running on E85 can safely support a higher compression ratio than one on standard pump gas. This is why a one-size-fits-all approach doesn't work; the right compression ratio ensures your engine is both powerful and reliable, and it’s a critical variable that gets dialed in perfectly during the final engine tuning process.
Closed Deck vs. Open Deck: Which is Right for You?
The stock FA20 engine block features an "open deck" design, meaning the cylinder walls are not fully supported at the top. This is fine for factory power levels, but it becomes a major liability in high-horsepower applications. The problem is, the stock FA20 engine has its limits. Closed deck designs provide additional strength and support for the cylinder walls, preventing them from flexing or cracking under extreme pressure. This modification is a preferred choice for serious builds, ensuring the block remains stable and reliable when you’re pushing for maximum performance with expert engine tuning services.
Common FA20 Build Myths, Busted
When you start researching built FA20 engines, you'll run into a lot of opinions online. Some will tell you it's the only way to make reliable power, while others will warn you about turning your daily driver into a garage queen. It's easy to get lost in the noise. Let's clear the air and tackle some of the most common myths about building an FA20. Understanding the truth behind these misconceptions will help you make a confident and informed decision for your Subaru.
Myth: Built Engines Aren't Reliable
Let's get this one out of the way first: there's a common misconception that built FA20 engines are fragile. The truth is, a professionally assembled engine using high-quality performance parts is significantly more durable than a stock engine pushed beyond its intended limits. Many drivers choose the FA20 platform because it has fewer widespread reliability issues than its predecessor, making it a fantastic foundation. A built motor doesn't create fragility; it creates a higher threshold for power and abuse. The key is in the quality of the components and the skill of the engine builder. When done right, a built long block gives you peace of mind, not more problems.
Myth: You Can Safely Push a Stock Block
It’s tempting to see how much power you can squeeze out of the stock block. While the factory FA20 is a capable engine, it has its limits, especially when it comes to the connecting rods and pistons. Pushing past 350 wheel horsepower on stock internals is asking for trouble and can lead to serious reliability issues. Instead of thinking of a built block as an extreme measure, view it as the correct way to build a high-horsepower car. It replaces the known weak points with components designed to handle the extra stress, giving you a safe and reliable platform for all your Subaru WRX upgrades. Don't risk catastrophic failure by chasing numbers on a stock engine.
Why Pro Installation and Tuning are Non-Negotiable
Your built long block is only as good as its installation and tune. This isn't the place to cut corners. A professional engine tune is absolutely critical; it’s the brain of the operation. A proper tune tells the car's computer how to make all the new, high-performance parts work together safely and efficiently. Without it, you risk damaging your brand-new engine. Expert engine tuning services ensure your air-fuel ratios are correct, your timing is optimized, and every component is functioning in harmony. Think of it as the final, essential step that protects your investment and realizes the engine's full, reliable potential. Budget for it from day one.
What to Expect from Your Engine Warranty
A warranty on a built engine is more than just a safety net; it’s a statement from the builder. It shows they stand behind their craftsmanship, materials, and the performance they promise. When you invest in a high-performance FA20 long block, the warranty protects that investment. However, it’s a two-way street. The builder provides coverage against defects, and you, the owner, have a responsibility to follow specific procedures to keep that coverage active.
Understanding the terms isn't about navigating legal jargon—it's about setting your new engine up for a long and powerful life. From the initial coverage period to the critical break-in process, knowing what’s expected of you is the key to a successful build. Think of it as the final chapter in the installation manual, ensuring your engine performs exactly as it was designed to. We’ll walk through what a typical warranty looks like, how to maintain it, and whether an extended plan makes sense for you.
What Does Your Coverage Period Include?
Most reputable engine builders offer a standard warranty, with a 12-month/12,000-mile term being a common benchmark of quality. This period covers defects in the builder's workmanship and the materials used in the long block. It’s the builder’s way of saying they trust their work to hold up under the demands of daily driving and spirited use. This coverage is designed to protect you from manufacturing flaws, not from issues caused by improper installation, a bad tune, or driver abuse. Before you buy, always read the fine print to understand exactly what is and isn't covered, so you can drive with confidence knowing your investment is secure.
How to Keep Your Warranty Valid
Maintaining your warranty is straightforward and centers on two critical phases: break-in and tuning. The first 1,000 miles are essential for seating the piston rings and ensuring all new components work together properly. During this period, you must avoid full throttle and keep RPMs below 4,000. It’s also important to constantly vary your speed, so set cruise control aside for a while. Once the break-in is complete, the final and most important step is getting a professional tune. Proper engine tuning services ensure your air-fuel ratios are safe, your timing is correct, and your engine is making power reliably, which is non-negotiable for both performance and warranty validation.
Is Extended Protection Worth It?
Some builders offer an extended warranty if you have the engine installed and tuned by one of their certified professional facilities. This can often double your coverage to something like 24 months or 24,000 miles. Is it worth it? For many owners, the answer is a clear yes. Having a single, trusted shop handle the entire process removes any guesswork. It ensures every component is installed to the builder’s exact specifications and that the final tune is perfectly matched to your specific setup. The added cost often buys you significant peace of mind, knowing that your entire build is backed by experts and protected for the long haul.
Essential Mods to Support Your New Long Block
Installing a performance long block is a massive step toward building your dream Subaru, but the engine itself is only part of the equation. To truly unlock its potential and ensure it runs reliably for years to come, you need to invest in the right supporting modifications. Think of it as building a team—your long block is the star player, but it needs a strong supporting cast to win the championship. These essential upgrades create a balanced system that can handle the power you’re about to unleash.
Why You Need a Better Fuel System and Turbo
A built FA20 is designed to handle significantly more power, but it can't create that power out of thin air. It needs more fuel and more air. If you’re aiming for big horsepower numbers, the stock turbo and fuel system simply won’t keep up. A larger turbocharger is necessary to force more air into the engine, while an upgraded fuel pump and injectors are required to deliver the fuel needed to match. Skimping here can lead to fuel starvation under high boost, a dangerous condition that can destroy your new engine. Matching these performance parts to your power goals is a critical step in building a reliable and potent setup.
Critical Cooling Upgrades: Radiator and Oil Cooler
More power always generates more heat. It’s a fundamental law of thermodynamics, and it’s one you can’t ignore when upgrading your engine. The factory cooling system is engineered for a stock motor, and it will quickly become overwhelmed when trying to manage the heat produced by a built FA20 running at its limit. An upgraded aluminum radiator will keep your coolant temperatures in check, while a dedicated oil cooler is essential for preserving your oil’s integrity. Hot oil loses its ability to lubricate properly, leading to premature wear on your engine’s internal components. These cooling modifications are non-negotiable for anyone serious about performance and longevity, forming a core part of any Subaru WRX upgrade plan.
Master the Engine Break-in Process
You’ve invested time and money into your new engine; now it’s time to protect that investment. The first 1,000 miles are the most critical period in your engine's life. This is when the piston rings seat against the cylinder walls, creating the tight seal necessary for optimal compression and performance. During this break-in period, it’s crucial to drive gently. Avoid high RPMs, hard acceleration, and constant speeds. Instead, vary your engine speed by driving on a mix of city streets and back roads. Following a proper break-in procedure ensures your engine will perform reliably for the long haul. Once you’ve completed the break-in, an oil change and expert tuning will finalize the process, dialing in your setup for maximum safe power.
The Critical Post Break-In Oil Change
Once you’ve completed the 1,000-mile break-in, your first oil change is one of the most important maintenance steps you'll take. As the new piston rings, bearings, and other components seat themselves, they shed microscopic metal particles. This is a normal and expected part of the process. The purpose of this initial oil change is to flush all of that debris out of the system before it can circulate and cause premature wear. After break-in, change the oil to remove these tiny metal particles and stick to a regular maintenance schedule with high-quality oil. This simple step is critical for protecting your investment and ensuring a long, healthy life for your new engine.
Monitoring Your Engine's Health with Gauges
With a high-performance engine, you can't afford to be in the dark about what's happening under the hood. The factory dashboard lights are designed to warn you when a problem is already severe, which is often too late. To protect your investment, install gauges to watch oil pressure, coolant temperature, and air-fuel ratios. These instruments provide real-time data, allowing you to catch small problems early before they become catastrophic failures. Think of them as your engine's vital signs monitor. A sudden drop in oil pressure or a spike in temperature gives you the crucial seconds needed to shut the engine down and prevent thousands of dollars in damage. It’s a small price to pay for invaluable peace of mind.
Why You Should Replace Fuel Injectors After Engine Failure
If you're replacing an engine that suffered a major internal failure, such as a spun bearing or broken piston, it's absolutely essential to replace your fuel injectors. When your old engine failed, it likely sent fine metal debris throughout the oil and fuel systems. These microscopic particles can easily contaminate your injectors, causing them to stick open or closed. A stuck injector can either starve a cylinder of fuel, creating a lean condition that leads to detonation, or flood it with fuel, washing oil from the cylinder walls. Either scenario can quickly destroy your brand-new long block. Reusing old injectors is a gamble that isn't worth the risk to your new performance parts.
Frequently Asked Questions
Why should I get a long block instead of just a short block? Choosing a long block is about getting a complete, professionally assembled core for your engine. While a short block provides a solid foundation, you are still responsible for sourcing, inspecting, and installing the cylinder heads. A long block eliminates that entire step. It arrives with the heads already matched and torqued to spec by the builder, ensuring perfect compatibility and saving you from potential headaches with a local machine shop. It's the most direct and reliable path to a fully built engine.
Can I still use my car as a daily driver with a built long block? Absolutely. One of the biggest misconceptions is that a built engine is only for the track. A professionally built and properly tuned long block is actually far more reliable for daily driving than a stock engine that's been pushed to its limits with bolt-on parts. The stronger internal components are designed to handle stress with ease, giving you peace of mind whether you're in traffic or on a weekend cruise.
What exactly do I need to do during the engine break-in period? The first 1,000 miles are crucial for the health of your new engine. The goal is to help the piston rings seat properly against the cylinder walls. To do this, you need to drive gently and vary the engine speed often. Keep the RPMs below 4,000, avoid hard acceleration, and don't use cruise control. Once you hit the 1,000-mile mark, an oil change is necessary to remove any initial metal particles. Following this process is the best way to ensure a long and reliable life for your investment.
Is the price of the long block the total cost for my build? No, the long block is the foundation of your build, but it's not the final cost. To support the new engine and its power potential, you must budget for several other critical components. This includes an upgraded fuel system, a larger turbo, a more efficient cooling system, professional installation, and a custom tune. Factoring these supporting modifications into your budget from the start is essential for a successful and reliable project.
How much power can I realistically make with a built FA20? A well-built FA20 long block can reliably handle over 600 horsepower, but the engine itself doesn't create that power alone. Your final horsepower number will depend entirely on your supporting modifications and your tune. A larger turbo, high-flow injectors, and an E85 tune will produce very different results than more conservative parts. The long block provides the strength to handle the power; your other choices determine how much power you actually make.