Honda K24a2 Engine Specs And Performance

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If you’re looking at a project car or just want to understand a legendary powerplant, the Honda K24A2 engine specs are a great place to start. This motor has earned its reputation for reliability and tunability, making it a favorite among enthusiasts and builders alike.

We’ll break down everything that makes this engine special. From its core design to its real-world performance, you’ll get a clear picture of what the K24A2 can do.

Honda K24A2 Engine Specs

Let’s get straight to the numbers. The K24A2 is a 2.4-liter, inline-four cylinder engine. It was primarily used in the 2004-2008 Acura TSX and the Japanese-market Honda Accord Euro R.

Here are the key specifications that define this engine:

  • Displacement: 2,354 cc (2.4L)
  • Bore x Stroke: 87 mm x 99 mm – This is a classic “square” design, favoring a balance of torque and high-RPM potential.
  • Compression Ratio: 11.0:1 – This is relatively high for a factory naturally aspirated engine, contributing to its efficiency and power.
  • Valvetrain: DOHC (Dual Overhead Cam) with i-VTEC – This is the full VTEC system, varying both intake and exhaust valve timing and lift.
  • Horsepower: 205 hp @ 7000 rpm (as rated in the Acura TSX)
  • Torque: 164 lb-ft @ 4500 rpm
  • Redline: 7100 rpm
  • Block Material: Aluminum with cast-in iron cylinder liners.
  • Cylinder Head Material: Aluminum.

What Makes the K24A2 Block Special?

The foundation of any engine is its block. The K24A2 uses an open-deck aluminum block. This design helps with cooling but is sometimes seen as less robust for extreme boost than a closed-deck block.

However, for most builds, its more than strong enough. The factory sleeves are durable, and the overall design is lightweight. Many people consider the K24A2 block one of the best starting points in the K-series family.

Inside the Cylinder Head: i-VTEC and More

The cylinder head is where the magic really happens. The K24A2 uses the sought-after “big port” head. This means the intake and exhaust ports are larger, allowing for better airflow compared to some other K24 variants.

The i-VTEC system is the full implementation. On the intake side, it uses VTEC (changing valve lift and duration) and VTC (continuously variable valve timing). On the exhaust side, it uses VTC only. This combination optimizes power across the entire RPM range, providing good low-end torque and a strong top-end pull.

The factory camshafts are also quite aggressive, which helps achieve that 205 horsepower figure without forced induction.

Stock Fueling and Induction

The engine uses multi-port fuel injection. The stock fuel injectors are sized appropriately for the engine’s natural aspiration but are often one of the first things upgraded when adding power mods.

The intake manifold is a two-part design with a dual-stage runner length system. This helps broaden the torque curve by optimizing airflow for both low and high RPMs. The throttle body is cable-driven, which many tuners prefer for its direct feel.

K24A2 Performance and Power Potential

In stock form, the K24A2 provides a smooth, linear powerband. The power delivery is predictable and makes for a great daily driver experience with a fun top-end kick when VTEC engages.

But the real story is the engine’s potential. The K24A2 is famously responsive to modifications. Here’s a typical progression of power gains:

  1. Basic Bolt-Ons: A cold air intake, header, and exhaust system can free up some restriction. Expect gains of 15-25 whp with a proper tune.
  2. Upgraded Camshafts: Swapping to more aggressive cams, like the ones from a K20A2, can significantly improve top-end power. This often requires valve spring upgrades.
  3. Forced Induction: This is where massive gains happen. With a turbocharger or supercharger kit, a well-built K24A2 can reliably produce 350-500 whp. Supporting mods like forged internals, a stronger head gasket, and larger fuel system components are crucial here.
  4. All-Motor Builds: By boring and stroking the engine, using high-compression pistons, race cams, and extensive head work, you can see over 250 whp naturally aspirated. These builds are expensive but offer incredible throttle response.

The Importance of Tuning

No matter what mods you add, a proper tune is non-negotiable. The factory ECU can be flashed using software like Hondata or K-Pro. This allows a tuner to optimize air/fuel ratios, ignition timing, and VTEC engagement points for your specific setup.

A good tune not only maximizes power but also ensures reliability. Never skip this step after making engine modifications.

K24A2 vs. Other K-Series Engines

It’s helpful to see how the A2 stacks up against its siblings. The most common comparison is with the K20A2 from the RSX Type-S.

  • K24A2 vs. K20A2: The K24 has more displacement (2.4L vs. 2.0L), giving it substantially more low-end and mid-range torque. The K20 tends to rev higher and may have a slight edge in peak horsepower per liter, but the K24’s torque makes it feel stronger in everyday driving and is often preferred for turbo builds.
  • K24A2 vs. K24A (from CR-V): The base K24A uses a smaller-port head and a less aggressive camshaft profile. It also often has a lower compression ratio. The A2 is the performance variant of the K24 family.
  • K24A2 vs. K24Z: The later Z-series engines (like the K24Z3 in the Civic Si) have some revisions, including a different head design and a higher redline. The power output is similar, but the Z3 head flows better at high RPM. Some builders actually combine a K24A2 block with a K24Z3 head for a potent combo.

Common Swaps and Applications

The K24A2 is a superstar in the engine swap world. Its compact size and excellent power make it a perfect fit for many older Honda and Acura chassis that originally came with less powerful engines.

Here are the most popular swap candidates:

  • Honda Civic (especially 1992-2000 EG/EK and 2001-2005 EP/EM): This is the classic swap. The K24A2 transforms these light cars into rocketships.
  • Honda Accord (1990s models): A great way to modernize and add serious power to a comfortable chassis.
  • Acura Integra (DC2/DC5): Dropping a K24 into an Integra creates a monster that retains the car’s brilliant handling with much more grunt.
  • Mini Cooper (R53): The “K-Mini” swap is a well-documented and incredible conversion, offering Toyota-level reliability with Honda performance.

Swapping requires mounting kits, wiring harness adapters, and often a custom exhaust. The aftermarket support for K-swaps is enormous, making the process very well-documented.

Reliability and Common Issues

Honda built the K24A2 to last. With routine maintenance, these engines can easily surpass 200,000 miles. However, there are a few known areas to watch:

  1. Oil Consumption: Some K24 engines can begin to consume oil as they age, often due to worn piston rings or valve stem seals. Regular oil level checks are a good habit.
  2. VTC Actuator Rattle: A common issue on startup is a brief rattling noise from the VTC actuator on the intake cam. This is often caused by low oil pressure on startup or a worn actuator. It’s more annoying than immediately damaging, but it should be addressed.
  3. Chain Tensioner Failure: The timing chain tensioner can fail, leading to a rattling noise and, in worst cases, jumped timing. Upgrading to a revised OEM or aftermarket tensioner is a common preventative fix.
  4. Head Gasket: While not as prone as some engines, pushing high boost levels on a stock head gasket is a risk. Upgrading to a MLS (Multi-Layer Steel) gasket is recommended for performance builds.

Sticking to a strict oil change schedule with quality synthetic oil is the best thing you can do for long-term health.

Maintenance Tips for Longevity

Follow these steps to keep your K24A2 running strong:

  1. Change oil and filter every 5,000 miles or less with a good 5W-30 synthetic.
  2. Use OEM or high-quality replacement parts for filters and ignition components.
  3. Check valve clearance as part of major service intervals (around 100k miles). The K-series uses shim-under-bucket adjusters, which are very stable but should be inspected.
  4. Replace the timing chain and components if you’re doing a high-mileage rebuild or performance build for peace of mind.
  5. Always let the engine warm up to operating temperature before revving it hard to allow oil to fully circulate.

Finding and Buying a K24A2 Engine

Since it’s been out of production for years, you’ll typically find these engines as used or JDM (Japanese Domestic Market) imports. Here’s what to look for:

  • Verify the Code: The engine code is stamped on the block, just below the cylinder head on the transmission side. Make sure it clearly says K24A2.
  • Check for Completeness: A complete engine should include the intake manifold, exhaust manifold, sensors, and often the alternator and starter. Missing parts add cost quickly.
  • Ask for Compression Test Results: A reputable seller should be able to provide a recent compression test. Healthy cylinders should show strong, even compression (usually 180-200 psi).
  • Look for Leaks and Damage: Inspect the engine for major oil leaks, cracked castings, or impact damage. Some minor grime is normal for a used engine.
  • Consider Mileage: Lower mileage is always better, but a well-maintained high-mileage K24 can still be a great candidate for a rebuild.

FAQ Section

What is the horsepower of a stock K24A2?

The factory rating for the Acura TSX application is 205 horsepower at 7000 rpm.

Is the K24A2 a good engine for turbocharging?

Yes, it is an excellent platform for turbocharging. Its strong block and good flowing head can handle significant boost with the proper supporting modifications and tune.

What cars came with the K24A2 engine from the factory?

The primary vehicle was the 2004-2008 Acura TSX. It was also used in the Japanese-market Honda Accord Euro R (CL7).

Can you put a K20 head on a K24A2 block?

Yes, this is a very popular hybrid build. Combining a K24A2 bottom end with a K20A2 cylinder head (often called a K24/K20 hybrid) creates an engine with great torque and an even higher-revving top end. It requires specific head gaskets and tuning.

What is the difference between K24A and K24A2?

The K24A2 is the performance version. It has a higher compression ratio (11.0:1 vs. 9.7:1 or 10.5:1), a larger-port cylinder head, more aggressive camshafts, and a dual-stage intake manifold. The A2 makes significantly more power.

How much does a used K24A2 engine cost?

Prices vary, but expect to pay between $1,500 and $3,000 for a complete, lower-mileage used engine in good condition. JDM imports often fall in this range.

The Honda K24A2 remains a benchmark for four-cylinder engine design. Its blend of smooth power, rugged reliability, and almost limitless potential for modification secures its place in the automotive hall of fame. Whether you’re keeping one stock in a TSX or building a swapped monster, understanding its specs and character is the first step to enjoying it for years to come.