Subaru Long Block vs. Short Block: Which Is Right?
You can have the best turbo, exhaust, and tune, but none of it matters if the heart of your Subaru isn't built to handle the power. A performance build is a system, and the engine is its foundation. Pushing a stock motor beyond its limits or pairing a new short block with worn cylinder heads is a recipe for failure. This is where a performance Subaru long block becomes the smartest investment you can make. It’s a complete, integrated package where every component, from the pistons to the valvetrain, is selected and assembled to work in harmony, ensuring your engine is ready for whatever you throw at it.
Key Takeaways
- A Long Block Simplifies Your Build and Ensures Reliability: By arriving with the cylinder heads and valvetrain professionally assembled to the short block, a long block removes the most common points of failure and saves you significant installation time.
- A Performance Long Block is the Foundation for Power: Stock engines aren't designed for increased horsepower. A performance-built long block, specific to your EJ or FA series engine, uses forged internals to provide the necessary strength for tuning and upgrades.
- Vet Your Supplier and Budget for the Full Job: Your investment is only as good as the builder behind it, so prioritize a strong warranty and transparency. Remember to budget beyond the engine for installation essentials and a professional tune to protect your new build.
What is a Subaru Long Block?
When you’re planning a serious engine build or recovering from a catastrophic failure, you’ll quickly run into two terms: short block and long block. Understanding the difference is crucial for getting your Subaru back on the road—or ready for the track—with the power and reliability you expect. A long block represents a more comprehensive engine solution, but what does that actually mean for you and your build? Let's break down exactly what a Subaru long block is, what comes inside, and why it’s often the smartest choice for performance enthusiasts.
Long Block vs. Short Block: What's the Difference?
Think of a short block as the engine's foundation. It’s the bottom half, containing the engine block, crankshaft, connecting rods, and pistons. While it’s a solid starting point, it’s incomplete. A long block, on the other hand, builds on that foundation by adding the top end. It includes everything in the short block assembly plus the cylinder heads, camshafts, and valvetrain. Essentially, a short block is the core, while a long block is a nearly complete engine, assembled and ready for your final components like the intake manifold and turbocharger. This distinction is key when planning the scope, budget, and complexity of your engine project.
What's Included in a Long Block Assembly?
When you get a long block, you’re receiving a professionally assembled package that goes far beyond the basic rotating assembly. Inside, you'll find the core short block components—the block, crank, rods, and pistons—already put together. The key additions are the cylinder heads, which are bolted on and sealed. These heads come fully equipped with camshafts to control the valves and the complete valvetrain (valves, springs, retainers). This means the most critical and sensitive parts of your engine have been matched and assembled in a controlled environment. All these high-quality performance parts work together to form the heart of your Subaru, taking much of the guesswork out of your build.
The Advantage of a More Complete Engine
Choosing a long block is about more than just convenience; it’s about reliability and peace of mind. Because a long block is a more complete assembly, it eliminates the risk of errors that can happen when matching heads to a short block. For high-performance builds, this is a huge advantage. You get a single, integrated unit where all components were assembled to precise specifications by experts. This ensures proper sealing, timing, and clearances from the start. This professional assembly provides a solid foundation for powerful and reliable engine tuning services, giving you confidence whether you’re on the street, track, or trail. It’s a more robust solution, especially for engines that have seen a lot of miles or are destined for serious power.
Finding the Right Long Block for Your Subaru
Choosing the right long block for your Subaru is the most critical step in your engine build. The decision starts with identifying your engine series, as this determines the foundation for all your performance goals. Whether you're driving a classic STI or a newer WRX, the engine platform dictates the available upgrades, power potential, and overall character of your build. At Crawford Performance, we specialize in building high-performance long blocks for a wide range of Subaru models, ensuring you get a reliable core that’s ready for whatever you throw at it.
The two main engine families you’ll encounter are the legendary EJ series and the more modern FA series. Each has its own strengths and a dedicated following in the Subaru community. The EJ25, for example, is a tuner’s dream with decades of development behind it, making it a popular choice for high-horsepower track and rally builds. On the other hand, the FA20 DIT brought direct injection to the WRX, offering a different path to power with its own unique tuning requirements. Understanding which engine your car has is the first step toward planning a build that meets your performance targets and budget.
The EJ25: Powering Your WRX, STI, or Forester
The Subaru EJ25 engine is an icon. If you own a 2002–2014 WRX, a 2004–2021 STI, or a Forester XT from 2004–2013, this is the powerhouse under your hood. Known for its incredible aftermarket support and raw, visceral feel, the EJ25 is the platform for some of the most ambitious Subaru builds. When you opt for a performance long block, you’re getting an engine built with forged internals and precision assembly designed to handle serious power. This makes it the perfect foundation for anyone looking to push their Subaru STI upgrades to the limit, whether on the track or a winding back road. It’s a proven platform with a legacy of performance.
The FA20 DIT: For Modern WRX Models
For owners of 2015–2021 WRX models, the FA20 DIT (Direct Injection Turbo) engine offers a more modern approach to performance. This engine introduced direct injection technology to the WRX lineup, providing a different power curve and unique tuning characteristics compared to its EJ predecessor. A performance-built FA20 long block addresses the known weak points of the stock engine, such as the pistons and connecting rods, replacing them with robust components ready for increased boost. Investing in a built FA20 long block is the smartest way to lay the groundwork for reliable power, ensuring your WRX upgrades are supported by a solid and durable core.
Performance vs. OEM: Which Build is for You?
Deciding between a performance-built long block and a stock OEM replacement comes down to your goals. An OEM engine is designed for factory power levels and daily driving. If you plan to add more power through tuning or bolt-on parts, you’ll quickly exceed its limits. A performance long block is the solution. It’s the ideal choice if you don't have the specialized tools, clean room, or time to assemble an engine yourself. It arrives professionally assembled with high-quality performance parts designed to handle significantly more stress, giving you a reliable foundation for a high-horsepower build right out of the crate. It’s a smart investment for long-term durability and peace of mind.
Understanding Subaru Long Block Costs
Investing in a long block is a major step toward building a powerful and reliable Subaru. Before you commit, it’s important to have a clear picture of the total cost. The price of the long block itself is just the starting point; performance level, engine type, and installation needs all play a role in your final budget. Let’s break down what you can expect to spend on your engine build.
Typical Price Ranges by Engine Type
The type of engine your Subaru uses is the biggest factor in determining the cost of a long block. Different engine series have unique architectures and components, which is reflected in their price. For example, performance-built EJ25 long blocks, common in the WRX, STI, and Forester XT, typically range from about $10,000 to $19,500. In contrast, the more modern FA20 DIT long blocks found in recent WRX models often fall between $16,500 and $19,000. These price differences are due to variations in design, component availability, and the engineering required to build them for high performance.
How Performance Upgrades Affect the Price
A stock-level long block will always be more affordable than one built to handle serious power. As you add performance upgrades, the cost increases accordingly. This is because high-horsepower builds require stronger, more expensive materials and precision machining. Forged pistons and connecting rods, upgraded bearings, and high-performance camshafts are common additions that increase an engine's strength and price tag. Advanced modifications like a 'closed deck' treatment, which reinforces the cylinder walls for extreme boost, also add to the final cost. Each upgrade is an investment in the engine's ability to reliably handle more power, making it a crucial consideration for your build goals.
Budgeting for the Full Installation
The price of the long block isn't your final number. To get your car back on the road, you need to account for the complete installation. This includes essential items like gasket kits, fluids, and break-in oil, which can add several hundred dollars to your budget. Some builders offer comprehensive installation kits that bundle everything you need. You also need to factor in labor costs if you aren't doing the work yourself. Finally, a professional tune is non-negotiable for a new engine build. Proper engine tuning services ensure your new long block runs safely and efficiently, protecting your investment and maximizing its performance from day one.
Why Choose a Long Block for Your Engine Build?
When your Subaru's engine needs a serious overhaul, you’re faced with a big decision: short block or long block? While a short block provides a solid foundation, opting for a
Choosing a long block means you’re getting a fully integrated system where the cylinder heads, camshafts, and valvetrain are perfectly matched to the bottom end. This synergy is critical for achieving reliable power. Instead of sourcing heads separately and hoping they pair well with your new short block, you get an entire package engineered to work together from day one. This saves you time, reduces installation complexity, and gives you a solid base for all your other performance parts. It’s the most direct path to a powerful and dependable engine.
Benefit #1: A Simpler, More Reliable Installation
One of the biggest advantages of a long block is the simplified installation process. The engine arrives with the short block, cylinder heads, camshafts, and valvetrain already assembled by expert technicians in a clean, controlled environment. This means critical steps like setting valve lash and torquing head studs are done to precise specifications, removing the guesswork and potential for error from your build. For both professional shops and experienced DIYers, this streamlined process saves hours of labor and reduces the risk of costly mistakes. You’re starting with a proven, professionally assembled core, which makes the rest of the installation much more straightforward.
Benefit #2: Peace of Mind with a Warranty
Investing in a performance engine is a significant commitment, and you deserve confidence in its quality. Reputable long blocks come with a warranty that covers the entire assembly. At Crawford Performance, every long block is backed by a 12-month/12,000-mile limited warranty. This is a crucial benefit. If you were to build an engine from a short block and experience an issue with the cylinder heads you installed, you’d be on your own. With a long block, the builder stands behind the complete unit, giving you a safety net and assurance that your investment is protected against defects in materials or workmanship.
Benefit #3: A Foundation for Serious Performance
If your goal is to make serious power, a long block is the ultimate foundation. The components aren’t just assembled; they’re selected to work in harmony to support your performance goals. The cylinder heads are ported and matched to the block’s capabilities, and the camshafts are chosen to optimize airflow for your specific application, whether you’re building a high-revving track car or a torque-focused overlander. This cohesive design ensures that your engine can handle the increased stress from larger turbos, aggressive tunes, and other Subaru WRX upgrades. It’s a balanced package built for power from the start.
Benefit #4: Built for Long-Term Durability
When you’re replacing a worn or damaged engine, you want its replacement to last. A long block provides superior long-term durability because it replaces nearly every major wear component in one go. Mating a new short block to high-mileage cylinder heads can create a weak link in your build, as worn valvetrain components can fail under the pressure of the new, stronger bottom end. A long block eliminates this risk by providing fresh, new components from the oil pan to the valve covers. This comprehensive refresh ensures every part is ready for the demands of performance driving, giving you a reliable engine that’s built to endure for years to come.
How to Choose the Right Subaru Long Block Supplier
Selecting a long block supplier is one of the most critical decisions you'll make for your Subaru build. You're not just buying a collection of parts; you're investing in the heart of your vehicle, the very core of its performance and reliability. The right supplier provides more than just an engine—they offer proven expertise, meticulous craftsmanship, and the assurance that your car will perform exactly as you envision. A great builder has a solid track record, stands behind their work with a comprehensive warranty, and is transparent about their process and the components they use. This choice will define your car's capabilities and your peace of mind for years to come, so it’s essential to partner with a company you can trust to deliver on its promises.
The Crawford Performance Advantage
When you're evaluating suppliers, the warranty is a direct reflection of the builder's confidence in their product. We provide a 12-month / 12,000-mile limited warranty on our Subaru long blocks because we know the quality of our craftsmanship and the premium components we use. This isn't just a policy; it's our promise that your engine is built to withstand the demands of spirited driving, whether on the track or an overlanding trail. This level of support gives you the confidence to push your Subaru to its limits, knowing it’s backed by decades of world-renowned engineering experience and an unwavering commitment to performance. It’s the peace of mind you need for a high-stakes investment.
What to Look for in a Builder
A reputable builder will always stand behind their work. Look for a supplier that offers a comprehensive warranty, as this protects your investment and signals a high standard of quality. Beyond the warranty, consider the builder's reputation within the Subaru community. Do they have a history of producing reliable, powerful engines? Are they known for using premium performance parts and maintaining meticulous assembly processes in a clean, controlled environment? A builder’s legacy is built on the long-term success of their engines, so choose one with a history of excellence, transparency, and satisfied customers who can vouch for their engine's durability and power.
Key Questions to Ask Before Buying
Before you commit, arm yourself with the right questions. A transparent builder will be happy to provide detailed answers. Start with the warranty: "What exactly does the warranty cover, and what are the limitations?" Then, ask about the build itself: "What specific brand and model of pistons, rods, and bearings are used?" and "What is your recommended engine break-in procedure?" Understanding the internal components is key to knowing the engine's limits. Finally, inquire about post-installation support, like their recommendations for professional engine tuning services to maximize performance safely. The quality of their answers will reveal their expertise and commitment to customer success.
Planning Your Installation
One of the biggest advantages of choosing a long block is the streamlined installation process. If you don't have the specialized tools, time, or clean-room environment to assemble an engine from a short block, a pre-assembled long block is the perfect solution. It arrives ready to be dropped in, significantly reducing the complexity and potential for critical errors during the build. This makes it a practical choice for enthusiasts who want a reliable, professional-grade engine without the logistical challenges of a full rebuild. It gets you back on the road faster, so you can start enjoying your new Subaru WRX upgrades with minimal downtime.
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Frequently Asked Questions
What other parts will I need to complete my long block installation? A long block serves as the core of your engine, but you will need to transfer parts from your old engine or buy new ones to complete the assembly. This typically includes your intake and exhaust manifolds, turbocharger, fuel system components, and accessories like the alternator and power steering pump. Think of it as the perfect opportunity to inspect and replace any worn items like belts and hoses to ensure your entire setup is fresh and reliable.
Is a performance long block overkill if I just daily drive my Subaru? Not at all. While a performance long block is a must-have for high-horsepower builds, it’s also an excellent choice for enhancing the long-term reliability of a daily driver. A professionally built engine with stronger internal components addresses the known weak points of the factory motor. This gives you a much more durable foundation that can handle daily demands with ease, providing peace of mind for years to come.
What is the break-in process for a new long block? The break-in period is crucial for seating the new piston rings and ensuring the longevity of your engine. The process generally involves driving the car gently for the first 1,000 to 1,500 miles, making sure to vary the engine speed and avoid constant RPMs. You should also stay away from high boost levels and full-throttle acceleration during this time. We provide detailed break-in instructions with every engine to guide you through this important step.
Do I need a professional tune after installing a long block? Yes, a professional tune is non-negotiable. A new performance long block has different components and airflow characteristics than a stock engine, and the factory ECU settings are no longer appropriate. A proper tune by an experienced Subaru specialist will calibrate your engine’s computer to the new hardware, ensuring it runs safely, makes reliable power, and operates at its full potential.
How is a long block different from a complete crate engine? While the terms are sometimes used interchangeably, a long block generally refers to the core engine assembly from the oil pan up to the valve covers. A complete crate engine is a more comprehensive package that often includes bolt-on components like the intake manifold, turbo, and wiring harness. A long block provides the essential foundation while giving you the flexibility to select the specific supporting parts that best fit your performance goals.