If you’re into engines, you’ve probably heard the name. The Honda K24 engine is a legend in the automotive world. It’s known for its incredible durability, smooth power, and huge potential for modification. Found in everything from family sedans to sports cars, this four-cylinder powerhouse has earned its reputation. This guide covers its history, common models, and why it’s so popular for swaps and tuning.
Honda K24 Engine
The K-series is Honda’s line of four-cylinder engines that began production in 2001. The K24, with its 2.4-liter displacement, is a standout member. It was designed to offer more torque and a broader powerband than the smaller 2.0-liter K20. You’ll find it in many Honda and Acura vehicles from the early 2000s right up to recent models. Its construction is classic Honda: an aluminum block and head, dual overhead cams (DOHC), and i-VTEC.
Where You’ll Find the K24: Common Applications
The K24 was used in a wide range of vehicles. This makes it relatively easy to find in junkyards or for sale as a complete swap package. Here are some of the most common cars that came with a K24:
- Honda Accord (2003-2007, 2008-2012)
- Acura TSX (2004-2008, 2009-2014)
- Honda CR-V (2007-2016)
- Honda Element (2003-2011)
- Acura RDX (2007-2012)
- Honda Odyssey (2008-2010, Japan market)
Key Design Features and Strengths
What makes the K24 so special? It’s a combination of smart engineering and robust materials. The engine was built to last and to perform.
- Closed-Deck Block: The cylinder walls are supported at the top, making the block very strong. This is great for handling high boost from turbochargers.
- i-VTEC System: This varies valve timing and lift on both the intake and exhaust camshafts. It helps with both fuel economy and high-RPM power.
- Forged Crankshaft: Many K24s come with a durable forged crankshaft from the factory, a sign of its high-performance roots.
- Chain-Driven Camshafts: Uses a timing chain instead of a belt. This means less maintenance and more reliability over the long term.
Popular K24 Variants and Their Differences
Not all K24 engines are the same. Honda made several versions with different power outputs and features. Knowing which one you have is key.
K24A2 (Acura TSX 2004-2008)
This is often considered the most desirable non-Type R K-series engine. It produces 200 horsepower and features a more aggressive camshaft profile, higher compression ratio (11.0:1), and a factory dual-stage intake manifold (DBW). It’s a fantastic starting point for any build.
K24A4 (Honda Accord 2003-2007)
A more common and economical variant. It makes about 160 horsepower. It has a lower compression ratio and a simpler intake manifold. While it makes less power stock, its strong block makes it a great candidate for forced induction.
K24Z3 (Acura TSX 2009-2014, Honda Accord 2008-2012)
This later model engine also produces 200 horsepower. It uses a revised i-VTEC system and a different head design (often called the “RBB” head). It’s a very modern and efficient engine, though some parts differ from the older K24A2.
Why the K24 is a Swap King
The Honda K24 engine has become the go-to swap for many enthusiasts. It’s particularly popular for older Honda chassis like the Civic, Integra, and even the S2000. Here’s why it’s so favored:
- Abundant and Affordable: Because it was used in so many common cars, used engines and parts are easy to find and relatively cheap.
- Torque Advantage: The extra 0.4 liters of displacement over the K20 means more low-end and mid-range torque. This makes street driving more enjoyable.
- Strong Aftermarket Support: Hundreds of companies make parts for the K-series. You can find anything from simple bolt-ons to complete race-built long blocks.
- Proven Reliability: Even when modified, a well-built K24 can be incredibly reliable. Its design is overbuilt for its original purpose, leaving lots of headroom.
Basic K24 Modifications for More Power
You don’t need to go all-out to wake up a K24. A few simple modifications can yield significant gains. Here’s a typical progression for a naturally aspirated (NA) build.
- Cold Air Intake & Exhaust: The first step is letting the engine breathe easier. A good intake and a full exhaust system (header, catalytic converter, muffler) can add 15-25 horsepower.
- ECU Tune: This is crucial. A custom tune from a reputable tuner (using Hondata or K-Pro) will optimize air/fuel ratios and ignition timing for your mods. It makes everything work together and can unlock hidden power.
- Intake Manifold: Swapping to a performance intake manifold, like the RBC from an Accord Euro, improves high-RPM airflow. It’s a popular and effective upgrade.
- Camshafts & Valvetrain: Upgraded camshafts change the valve timing for more power. This often requires stronger valve springs and retainers, especially for high-RPM use.
- High-Compression Pistons: For an all-out NA build, installing pistons that raise the compression ratio is the final step. This requires opening the engine block, so it’s a major job.
Forced Induction: Turbo and Supercharger Kits
If you want big power, forced induction is the answer. The K24’s closed-deck block handles boost exceptionally well. With a turbocharger or supercharger kit, 400+ horsepower is very achievable on a stock block with proper tuning.
- Turbocharging: Offers the highest potential power gains. A turbo system uses exhaust gases to spin a turbine, forcing more air into the engine. It requires intercoolers, blow-off valves, and significant fuel system upgrades.
- Supercharging: A supercharger is driven by the engine’s crankshaft, providing instant boost and a linear power delivery. It’s often seen as more predictable than a turbo, but can have slightly lower peak power potential.
Remember, a good tune is even more critical with forced induction. Poor tuning is the fastest way to destroy an engine under boost.
Common Issues and What to Watch For
No engine is perfect, and the K24 has a few known weak points. Being aware of them can save you time and money. Most of these are manageable with regular maintenance or simple upgrades.
- Oil Consumption: Some K24s, especially earlier models, can burn oil. This is often due to worn piston rings or valve stem seals. Checking your oil level regularly is a good habit.
- Timing Chain Tensioner: The factory automatic tensioner can fail over time. A failing tensioner causes a rattling noise on startup. Upgrading to a revised OEM or manual tensioner is a common fix.
- VTC Actuator Rattle: The Variable Timing Control actuator on the intake cam can wear out, causing a distinct rattle on cold starts. Replacing the actuator usually solves the problem.
- Block Porosity (Early Models): A very small number of early K24 blocks had casting issues that could lead to coolant leaks. This is rare, but worth mentioning. Later blocks do not have this concern.
The K24 Swap Process: A Simplified Overview
Swapping a K24 into a car that didn’t come with one is a major project. It’s not for beginners, but understanding the steps helps. Here’s a basic outline.
- Source a Complete Donor Package: You need more than just the engine. Aim for the engine, transmission, wiring harness, and ECU all from the same donor car.
- Gather Swap-Specific Parts: You’ll need motor mounts, shift linkage, and a conversion harness to make your car’s electronics talk to the K24 ECU. Companies like Hybrid Racing and K-Tuned specialize in these parts.
- Engine Bay Preparation: This involves removing the old engine and modifying the bay if necessary. Some chassis need a small notch in the frame rail for the K24’s larger oil pump.
- Installation and Wiring: Dropping the new engine in is the easy part. Wiring is where most people struggle. Label every connector carefully from the donor harness.
- Cooling and Exhaust: You’ll need custom radiator hoses and an exhaust system made to fit your chassis with the K24 headers.
- Tuning and First Start: Before you try to start it, ensure all fluids are in and the timing is correct. The first start is a nervous but exciting moment.
K24 vs. K20: Which One is Right for You?
This is a classic debate. The K20 (2.0L) is known for its incredibly high-revving nature, often found in the Civic Si and Type-R models. The K24 offers more displacement and torque. Your choice depends on your goals.
- Choose a K20 if you want the highest possible RPMs for a track-focused, naturally aspirated build. It loves to rev above 8000 RPM.
- Choose a K24 if you want more street-friendly torque, are planning a turbo build, or want the most cost-effective power. The powerband is broader and more usable daily.
Many people even combine them, using a K24 block with a K20 cylinder head (a “K24/K20 frankengine”) to get the best of both worlds.
Routine Maintenance for Longevity
To keep your K24 running strong for 200,000 miles or more, stick to a strict maintenance schedule. These engines respond well to care.
- Oil Changes: Use a high-quality synthetic oil (like 5W-30) and change it every 5,000 miles or less, especially if you drive hard.
- Timing Chain: While it’s a “lifetime” part, the chain and guides should be inspected if you hear unusual noises. The tensioner should be checked regularly.
- Coolant: Flush the cooling system every 60,000 miles or 5 years. Use Honda Type 2 coolant or a reliable equivalent to prevent corrosion.
- Spark Plugs: Replace spark plugs with the correct OEM-spec plugs every 60,000-100,000 miles, depending on your tune and mods.
- Valve Adjustment: The K24 uses mechanical lash adjusters, but checking valve clearance is still a good idea during major services.
FAQ Section
What is the horsepower of a stock Honda K24 engine?
It varies by version. The most powerful common US variant, the K24A2, makes 200 horsepower. The base K24A4 makes about 160 horsepower. Later models like the K24Z3 also make 200 horsepower.
Is the K24 engine reliable?
Yes, extremely. With proper maintenance, it’s known for easily surpassing 250,000 miles. Its robust design is a key reason for its popularity in swaps and tuning.
Can you turbo a stock K24 block?
Absolutely. The stock closed-deck block can handle significant boost. Many people reliably run 400-500 horsepower on a completely stock internal K24 with a good turbo kit and, most importantly, a professional tune.
What’s the difference between a K20 and K24?
The main difference is displacement: 2.0 liters vs. 2.4 liters. The K24 has a longer stroke, giving it more torque. The K20 typically has a higher redline and is more focused on peak horsepower at high RPMs.
What cars came with a K24 engine?
Many Honda and Acura models used it, including the Honda Accord, CR-V, Element, Acura TSX, and RDX from various model years between 2002 and 2016.
How much does a K24 engine swap cost?
Costs vary widely. A budget swap using a junkyard engine and used parts can start around $3,000 if you do the work yourself. A full turn-key swap with a fresh engine, new mounts, harness, and tuning can easily exceed $8,000-$10,000.
The Honda K24 engine’s blend of accessibility, strength, and performance potential is hard to beat. Whether you’re keeping a TSX on the road, building a weekend track car, or doing a full swap, it offers a fantastic platform. Its community and aftermarket are vast, so information and parts are never far away. Understanding its basics is the first step toward making the most of this modern classic.