Comparing the Top FA20 Long Block Builders
You love your WRX or BRZ, but you’ve hit a wall. You’ve added an intake, an exhaust, and a tune, but you know there’s more power to be had. The problem is, the stock FA20 engine has its limits, especially when it comes to the connecting rods and pistons. Pushing past 350 wheel horsepower is a risky game of chance with the factory internals. This is where a built FA20 long block comes in. It’s not just a replacement; it’s a complete re-engineering of the engine’s core, designed to handle the stress of serious power. This guide will walk you through everything you need to know about making this foundational upgrade.
Key Takeaways
- Go Beyond Stock Limits Safely: An FA20 long block is the essential foundation for pushing past the stock engine's ~350 whp limit. It replaces failure-prone factory parts with forged internals, creating a durable core that can handle a larger turbo and more aggressive tuning.
- Evaluate the Builder, Not Just the Price: When choosing a long block, prioritize a builder's quality control, professional assembly process, and warranty. These factors are far more important for long-term reliability than horsepower claims or the initial cost.
- Plan for Supporting Mods and a Tune: A built engine is only one part of a successful build. You must budget for critical supporting components like an upgraded fuel system and a professional tune to ensure your new engine runs safely and performs at its peak.
What is an FA20 Long Block?
If you're looking to get serious power out of your Subaru, you've likely heard the term "FA20 long block." An FA20 long block is a performance engine assembly that serves as the heart of a high-output build. It includes the core components: the engine block, cylinder heads, and all the critical internal parts like pistons, connecting rods, and the crankshaft. These assemblies are specifically engineered to handle significantly more power and stress than a stock engine.
For many Subaru enthusiasts, upgrading to a built long block is the next logical step after pushing the limits of the factory FA20. The stock engine is great for daily driving, but its components have known weaknesses that can become failure points under increased boost or aggressive driving. A performance long block replaces those weak links with stronger, forged components, providing a reliable foundation for a turbo upgrade, a supercharger, or a demanding track setup. It’s the solution for building a car that is both powerful and durable.
The Boxer Engine Design
The FA20 is a "boxer" engine, also known as a flat-four. This means its four cylinders are arranged horizontally, with two on each side, moving in and out like a boxer throwing punches. This unique design is a hallmark of Subaru engineering and offers some distinct advantages. By laying the cylinders flat, the engine has a much lower profile than a traditional inline or V-style engine. This lowers the vehicle's overall center of gravity, which directly translates to better handling, less body roll in corners, and a more stable feel on the road. The boxer configuration also naturally cancels out certain vibrations, resulting in smoother operation and that iconic Subaru rumble that enthusiasts love.
Long Block vs. Short Block vs. Complete Engine
When you're shopping for engine components, you'll see terms like short block, long block, and complete engine. Understanding the difference is key to planning your build. A short block is the most basic assembly, consisting of the engine block, crankshaft, pistons, and connecting rods. A Subaru long block takes it a step further by including the cylinder heads and valvetrain components. However, it doesn't include external parts like the intake manifold, exhaust headers, or fuel system. A complete engine, or crate engine, is the most comprehensive option, arriving fully assembled and ready to be dropped into your car. For most performance builds, the long block offers the perfect balance of convenience and customization.
FA20 Long Block: Performance and Specs
The FA20 engine is a fantastic platform right out of the box, offering a great balance of performance and daily drivability. However, like any stock engine, it has its limits. When you start pushing for more power, you’ll quickly find the factory components can only take so much stress. Understanding these limitations is the first step in building a reliable, high-performance Subaru. A built long block isn't just about adding power; it's about creating a durable foundation that can handle whatever you throw at it. Let's look at the stock FA20's capabilities and where it needs reinforcement.
Power Capabilities
From the factory, the FA20 engine can reliably handle around 300 to 350 wheel horsepower (whp). For many drivers, this is plenty of power for an engaging experience. But if your goals include significant power gains from a larger turbo or more aggressive tuning, you're entering territory where the stock internals become a liability. Pushing past that 350 whp threshold on stock components is a gamble. To safely make more power, you need an engine built with stronger materials, which is why a long block with upgraded performance parts is essential for any serious build.
Torque Limits
While horsepower gets all the attention, torque is what really tests an engine's strength. The stock connecting rods in the FA20 are a known weak point and can safely handle about 350 ft-lbs of torque. An aggressive tune or forced induction can easily push torque levels beyond this point, risking catastrophic engine failure. This is why simply turning up the boost isn't a sustainable path to power. To exceed this limit safely, you need forged connecting rods and pistons. Our engine tuning services always take these mechanical limits into account to ensure your build is both powerful and reliable.
Key Internal Components
A performance-built FA20 long block directly addresses the known weak points of the stock engine by replacing components prone to failure under high stress. This means swapping the factory cast pistons and weaker connecting rods for much stronger forged alternatives. These key upgrades create a robust rotating assembly capable of handling significantly more power and torque than the original setup. By reinforcing the engine's core, a built long block provides the peace of mind you need to pursue serious Subaru WRX upgrades and build the powerful, reliable car you want.
The Crawford Performance FA20 Long Block
When you’re ready to move beyond the limits of the stock FA20 engine, you need a solution built for power, reliability, and longevity. At Crawford Performance, we don’t just rebuild engines; we re-engineer them from the ground up to create a foundation capable of handling whatever you throw at it. Our approach is born from decades of track-tested experience, ensuring every component works in harmony to deliver consistent, usable power.
Our FA20 long block is the result of identifying and systematically eliminating the weak points of the original factory engine. We’ve spent countless hours on the dyno and the racetrack to develop a package that provides the strength you need for forced induction and aggressive tuning. This isn't just a replacement—it's a fundamental upgrade designed for the serious Subaru enthusiast who demands more from their vehicle.
Our Built Engine Packages
Our philosophy is simple: build it right, build it strong. We address the FA20’s known vulnerabilities by replacing critical internal components with superior, high-strength alternatives. The stock pistons and connecting rods are the first to go, swapped out for robust forged units that can withstand significantly higher cylinder pressures and heat. This strategic reinforcement is what allows our performance parts to truly shine, creating an engine that is not only more powerful but also far more durable than its stock counterpart. Every engine is assembled with meticulous care in a controlled environment to ensure perfect clearances and reliable performance from day one.
Performance Specs
The FA20 platform has incredible potential, but unlocking it requires addressing its inherent limitations. Our built engines are engineered to maximize the engine’s natural strengths—like its low center of gravity and rev-happy nature—while fortifying its weaknesses. The result is a balanced and responsive powerhouse that transforms the driving experience of your WRX or BRZ. By creating a solid foundation, our long blocks allow for more aggressive engine tuning services and higher boost levels without compromising reliability. This means you can push your car harder, knowing the engine is built to take it.
Our 12-Month/12,000-Mile Warranty
We stand behind our craftsmanship with a comprehensive 12-month/12,000-mile warranty on all our built engines. This isn't just a promise; it's a reflection of our confidence in the quality of our components and the precision of our assembly process. Investing in a built engine is a major decision, and we believe you should have complete peace of mind. Our warranty ensures that your investment is protected, allowing you to focus on enjoying the incredible performance of your newly upgraded Subaru. It’s our commitment to you and a testament to the reliability we build into every single engine that leaves our shop.
Comparing FA20 Long Block Builders
When you start shopping for a built FA20, you’ll notice a few names come up repeatedly. Each builder brings something different to the table, from horsepower ratings to warranty policies. Understanding these differences is key to choosing the right foundation for your build. While we stand by our own engine packages, we believe an informed driver is a happy driver. Let's look at some of the other top builders in the Subaru community so you can see how the options stack up.
IAG Performance
IAG Performance is a well-known name in the Subaru world, offering a range of staged engine blocks. Their IAG 600 FA20 DIT Long Block is a popular choice for 2015-2021 WRX owners. These engines arrive fully assembled with timing components pre-set, which can simplify the installation process. Inside, you’ll find upgraded forged connecting rods and pistons designed to handle more power than the stock components. IAG also provides a 12-month/12,000-mile warranty, which can be extended if the engine is installed and tuned by one of their certified facilities. This makes them a solid option for those looking for a proven, step-by-step upgrade path.
RalliSpec
RalliSpec takes a very detail-oriented approach to its engine builds. Instead of just replacing parts, their engineering focus is on identifying and correcting the known weaknesses of the factory FA20 engine. This means their long block options are built from the ground up with enhanced reliability in mind, especially for high-performance driving. If your main goal is to build an engine that can confidently withstand the rigors of track days or aggressive street driving, RalliSpec’s focus on reinforcing the platform’s weak points makes them a compelling choice. They build engines designed for durability under serious stress.
GCH Longblock Racing
If you're chasing big power numbers, GCH Longblock Racing is a builder to consider. Their Stage 1 Long Block for the 2015-2021 WRX and other FA20 platforms is rated to handle up to 625 horsepower. This capability comes from stronger forged race pistons and connecting rods. GCH also highlights their strict in-house building and quality control process, ensuring every engine meets their performance standards before it ships out. For drivers planning a build with a larger turbo and supporting fuel system upgrades, GCH provides a robust foundation designed specifically for high-output applications.
Subaru OEM
You can always go directly to the source and purchase a Subaru OEM long block. This option gives you a brand-new engine built to the exact specifications of the one that came in your car from the factory. It’s the most straightforward way to ensure perfect compatibility and restore original performance. While an OEM block won't have the forged internals needed for significant power increases, it offers unmatched peace of mind for those simply looking to replace a tired or damaged engine. It’s typically a more expensive route than aftermarket options, but for a daily driver where reliability is the absolute top priority, it’s a dependable choice.
Which Subarus Have the FA20 Engine?
The FA20 is a modern 2.0-liter flat-four Boxer engine that has become a cornerstone of the Subaru performance world. Its design maintains the classic Boxer benefits—a low center of gravity for improved handling and inherent smoothness—while introducing modern technologies like direct injection. This engine is incredibly versatile, appearing in both naturally aspirated and turbocharged forms across several popular enthusiast platforms. Its robust design and tuning potential have made it a favorite for drivers looking to extract more power from their cars.
Whether you’re carving corners in a lightweight coupe or enjoying the all-wheel-drive grip of a sport sedan, there's a good chance the FA20 is the heart of the machine. Its widespread use means there is a massive community and extensive aftermarket support, making it an excellent platform for building a high-performance vehicle. While it’s a Subaru engine through and through, its influence also extends to a celebrated collaboration with Toyota, placing this impressive Boxer engine in even more drivers' hands. Understanding which models carry the FA20 is the first step in planning your performance journey.
Subaru BRZ
The Subaru BRZ is a pure sports coupe built around the driver, and its engine is a perfect match for that philosophy. It features the naturally aspirated version of the FA20, which produces 200 horsepower and 151 lb-ft of torque. This engine was engineered for responsiveness and a linear powerband that encourages you to wind it out to its 7,000 RPM redline. The focus here isn't on raw power but on balance and agility. The FA20's lightweight, compact design contributes to the BRZ's low center of gravity and near-perfect weight distribution, making it one of the most engaging and fun-to-drive cars on the market.
Subaru WRX
The Subaru WRX takes the FA20 platform in a completely different direction with the FA20 DIT (Direct Injection Turbo) engine. This variant is built for serious performance, delivering a potent 268 horsepower right from the factory. The key difference is the addition of a twin-scroll turbocharger paired with direct fuel injection, which provides instant throttle response and a wide, flat torque curve. This engine transforms the WRX into a rally-inspired sport sedan with thrilling acceleration. For enthusiasts, the FA20 DIT is an incredible starting point for creating a true powerhouse, with plenty of room to grow with the right Subaru WRX upgrades.
Toyota 86 & Scion FR-S
Thanks to a landmark collaboration between Subaru and Toyota, the FA20 engine also powers the Toyota 86 and its predecessor, the Scion FR-S. These coupes share the same chassis and powertrain as the Subaru BRZ, meaning they are equipped with the same naturally aspirated 2.0-liter Boxer engine. Just like in the BRZ, the FA20 in the 86 and FR-S produces 200 horsepower and 151 lb-ft of torque, delivering an identical driving experience focused on balance, precision, and driver feedback. This partnership brought the exceptional engineering of the FA20 to an even broader audience of sports car enthusiasts.
How to Choose an FA20 Long Block
Selecting a built FA20 long block is one of the most significant investments you can make in your Subaru. It’s the heart of your build, and the right choice will provide reliable power for years, while the wrong one can lead to frustration and costly repairs. To make a confident decision, you need to look beyond the horsepower numbers and evaluate the builder on a few key criteria: the quality of their components, the expertise of their assembly process, and the clarity of their policies. A builder who is transparent about these details is one you can trust to power your project.
Quality Control
A builder’s commitment to quality control is paramount. This goes beyond simply using good parts; it involves a meticulous process of inspecting, measuring, and testing every component. A performance-built FA20 long block addresses the known weak points of the stock engine, replacing components like pistons and connecting rods with superior alternatives. Ask potential builders about their processes, like blueprinting and how they verify clearances. A builder who stands behind their work with a solid engine warranty is demonstrating confidence in their quality control and giving you peace of mind.
Forged Internals
The stock FA20 is a capable engine, but pushing it beyond its intended limits reveals well-known weak points that need to be addressed for reliable performance. This is where forged internals come in. Forged pistons and connecting rods are created under immense pressure, resulting in a denser, stronger component compared to stock cast parts. This strength is essential for handling the increased cylinder pressures from higher boost levels. When comparing long blocks, verify that they include high-quality forged internals from reputable brands. These are the core performance parts that will allow you to safely make more power.
Professional Assembly
The best parts in the world won’t matter if they aren’t assembled correctly. Building a high-performance engine is a craft that requires precision, expertise, and an impeccably clean environment. Look for builders with a proven track record and experienced technicians who specialize in Subaru platforms. Building your FA20 engine is a major step toward creating the high-performance WRX or BRZ you've envisioned, and you want it in the hands of experts. Professional assembly ensures every bolt is torqued to spec and every clearance is perfect, which is critical for engine longevity and performance.
Core Exchange Policies
Most long block builders operate on a core exchange basis. This means you’ll pay a deposit (a "core charge") which is refunded when you send them your old, usable engine. Before committing, make sure you fully understand the builder’s core policy. What are the conditions for a core to be considered acceptable? How long do you have to return it? A clear and fair policy can save you a significant amount of money and prevent unexpected costs. This process allows builders to secure engine blocks for future Subaru WRX upgrades and helps keep costs down for the entire community.
Breaking Down the Cost of an FA20 Long Block
Investing in a built FA20 long block is one of the most significant upgrades you can make to your Subaru. While it’s exciting to think about the performance gains, it’s also important to have a clear understanding of the total cost. The price tag on the engine itself is just one piece of the puzzle. To budget properly, you need to account for the base engine, installation labor, and the essential supporting modifications required to make everything run smoothly and reliably. Let’s walk through what you can expect to spend.
Base Engine Price
The cost of an FA20 long block varies widely based on the builder, the quality of the internal components, and its power-handling capabilities. For a high-horsepower build, an engine like the IAG 600 FA20 DIT Long Block is rated for up to 600 BHP and is priced around $16,500. For those with more modest goals or a tighter budget, options like GCH Longblock Racing’s Stage 1 package start at approximately $5,600. Keep in mind that most builders also require a core deposit, which is a refundable fee you get back after sending them your old engine.
Installation Costs
Once you’ve purchased your long block, the next expense is installation. Labor rates differ from shop to shop, but there’s some good news: because a long block comes fully assembled, the installation process is fairly straightforward. A skilled technician typically just needs to transfer over external components from your old engine, which can often be done in a single day. This is also the ideal time to replace related wear-and-tear items. For example, installing new timing components like chains, tensioners, and rails can add around $1,900 to the final bill but is a smart move for long-term reliability.
Budgeting for Supporting Mods
A built engine can’t reach its full potential without the right supporting parts. The most critical step after installation is a professional engine tune. A proper tune ensures all your new components work together safely and efficiently, protecting your investment from catastrophic failure. You should also plan for an adjusted maintenance routine. For modified FA20 engines, it’s wise to perform more frequent oil changes—typically every 3,000 to 4,000 miles—to maintain engine health. Factoring these reliability mods and services into your budget from the start will save you from costly surprises down the road.
Best Mods for Your New FA20 Long Block
Installing a built FA20 long block is a serious investment in your Subaru's performance, but it's only the first step. To truly tap into its potential, you need a set of supporting modifications that work in harmony with your new engine. Think of the long block as the strong foundation; now it's time to build the high-performance structure on top of it.
Choosing the right components is crucial for maximizing power, maintaining reliability, and protecting your investment. From forced induction to a precision tune, each part plays a vital role in creating a balanced and powerful build. Let's walk through the essential upgrades you should plan for after your new FA20 is in place.
Forced Induction: Turbos & Superchargers
A properly built FA20 can reliably handle over 600 horsepower, which is more than enough for thrilling track days or daily driving. To reach those numbers, you'll need a forced induction system, like a turbocharger or supercharger. However, simply adding a bigger turbo isn't enough. More power creates more stress and heat, so you need the right supporting performance parts to manage it. This includes a larger intercooler to cool the compressed air, an upgraded radiator for better engine cooling, and a robust clutch to handle the extra torque.
Fuel System Upgrades
More air from a turbo or supercharger requires more fuel to maintain a safe air-fuel ratio. The stock fuel system in a WRX or BRZ simply can't keep up with the demands of a high-powered build. At a minimum, you'll need to install a higher-flow fuel pump and larger fuel injectors to deliver the necessary volume. If you plan on running E85 fuel for maximum power output, remember that it requires about 30% more fuel than gasoline. This makes upgrading your fuel system an absolute necessity for a safe and powerful setup.
The Importance of a Solid Tune
A professional engine tune is the single most important step after installing any performance parts. It’s the brain of the operation, ensuring all your new components work together safely and efficiently. A skilled tuner adjusts fuel maps, ignition timing, and boost levels to optimize performance while keeping engine parameters within safe limits. Any time you add a part that changes how your engine breathes, like an intake, exhaust, or turbo, you must get professional engine tuning services. Skipping this step is the quickest way to damage your new engine.
Intake & Exhaust Upgrades
For your engine to make more power, it needs to breathe better. Upgrading the intake and exhaust systems is essential for maximizing the efficiency of your forced induction setup. A high-flow air intake allows the turbo to draw in more cool, dense air, while a less restrictive exhaust system helps the engine expel gases more easily, reducing backpressure and improving turbo spool. These Subaru WRX upgrades are fundamental to helping your built FA20 reach its full performance potential and should be planned alongside your turbo and fuel system modifications.
How to Maintain Your Built FA20 Long Block
Investing in a built FA20 long block is a serious commitment to performance. To protect that investment and ensure your engine delivers reliable power for years to come, you need an equally serious maintenance plan. A built motor has different needs than a stock engine, and staying on top of a few key areas will make all the difference. Think of it as the foundation for all the fun you're about to have on the road or track.
Proper care goes beyond just topping off fluids; it involves a proactive approach to keeping your engine clean, lubricated, and running within safe parameters. By following a consistent schedule and installing a few key supporting mods, you can prevent common issues and enjoy the full potential of your high-performance Subaru. Let's walk through the essential steps for maintaining your built FA20.
Oil Change Schedule
For a modified FA20 engine, the standard oil change interval simply won't cut it. The increased stress and heat generated by higher performance levels break down oil much faster. To keep your engine internals clean and properly lubricated, you should cut the factory-recommended oil change schedule in half. This means changing your oil and filter every 3,000 to 4,000 miles. If you frequently push your car hard on the track or during spirited drives, sticking closer to the 3,000-mile mark is your best bet. This simple, consistent practice is one of the most effective ways to ensure the longevity of your built motor.
Installing an Air-Oil Separator (AOS)
If there's one supporting modification every FA20 owner should have, it's an Air-Oil Separator (AOS). The FA20 is a direct-injection engine, which makes it susceptible to carbon buildup on the intake valves. An AOS intercepts oily vapors from the crankcase ventilation system before they can enter your engine's intake. This prevents that oil from baking onto your valves, which can lead to reduced airflow, poor performance, and even dangerous engine knock. Installing one of our Crawford Performance Air-Oil Separators is a crucial step in maintaining engine reliability and power.
Carbon Cleaning
Even with an AOS, some carbon buildup is inevitable over time. To keep your engine running at peak efficiency, you should schedule a professional carbon cleaning every 40,000 to 60,000 miles. This service, often called "walnut blasting," uses crushed walnut shells to safely scrub carbon deposits from the intake valves and ports without damaging the metal surfaces. Removing this buildup restores proper airflow, ensuring your engine runs smoothly and continues to produce the power you expect. It’s a vital part of the long-term care plan for any direct-injection engine, especially a high-performance one.
Monitoring Engine Health
You can’t fix a problem you don’t know you have. Using a tool like a Cobb Accessport or a set of dedicated gauges is essential for keeping tabs on your engine's vital signs. Pay close attention to metrics like your air-fuel ratio (AFR), boost levels, and fluid temperatures. Monitoring this data in real-time allows you to spot small irregularities before they escalate into major failures. This proactive approach, combined with professional engine tuning services, empowers you to make informed decisions and significantly extend the life of your built FA20 long block.
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Frequently Asked Questions
Why should I get a built long block instead of just upgrading my stock engine? Think of a built long block as a strong foundation for your house. While you can add parts to your stock engine, its core components—like the pistons and connecting rods—were never designed for high power levels. A built long block replaces those factory weak points with much stronger, forged parts from the start. This creates a reliable base that can safely handle the stress of a bigger turbo and an aggressive tune, preventing catastrophic failure down the road.
At what power level does a built FA20 long block become necessary? While there isn't a single magic number, the stock FA20 internals are generally considered at risk once you exceed 350 wheel horsepower or 350 ft-lbs of torque. The factory connecting rods are a well-known weak point and can fail when pushed beyond this threshold. If your performance goals require power levels above this range, a built long block isn't just a good idea—it's essential for keeping your engine in one piece.
What does an engine warranty typically cover? A warranty on a built engine protects you from defects in the parts or the assembly process. It’s the builder’s promise that they’ve used quality components and put them together correctly. However, this coverage depends on you doing your part. Actions like improper installation, failing to get a professional tune, overheating the engine, or running it low on oil will almost certainly void your warranty. Always follow the builder's specific break-in and maintenance instructions.
Is installing a long block a difficult project? Installing a long block is a significant job, but it's less complex than a full engine rebuild since the core components arrive pre-assembled. The process involves transferring external parts like your intake manifold, turbo, and accessories from the old engine to the new one. This requires specialized tools and a high level of mechanical skill. For most owners, we strongly recommend having the installation done by a professional shop with experience in Subaru performance.
What is the most critical step after my new long block is installed? The single most important thing you must do is get a professional engine tune. Your new engine and supporting parts create a system that is completely different from the factory setup. A skilled tuner will precisely calibrate your car's computer to match the new hardware, optimizing performance while ensuring all parameters are safe. Skipping a professional tune is the quickest way to damage your new investment.