Description

k24a2 engine

The K24A2 engine is a popular high-performance variant of Honda’s K24 series of engines, specifically found in the Acura TSX (2004-2008). It’s part of Honda’s K-series family, which is known for its versatility and potential for tuning. The K24A2 has become a favorite among Honda enthusiasts due to its combination of power, reliability, and aftermarket support.

Key Features of the K24A2 Engine

1. Displacement:
   • The K24A2 has a displacement of 2.4 liters (2354 cc), making it larger than the K20 series engines, which are commonly 2.0 liters. This increased displacement helps provide more torque at lower RPMs, which is beneficial for both daily driving and performance applications.
2. DOHC i-VTEC Technology:
   • Like other K-series engines, the K24A2 features Honda’s DOHC (Dual Overhead Cam) i-VTEC system. The intelligent Variable Valve Timing and Lift Electronic Control (i-VTEC) adjusts valve timing for both intake and exhaust, optimizing performance, fuel economy, and emissions.
   • The K24A2’s i-VTEC engages at around 6,000 RPM, providing a noticeable increase in power at higher revs while maintaining good fuel economy at lower speeds.
3. Power Output:
   • The K24A2 produces 200 horsepower at 6800 RPM and 166 lb-ft of torque at 4500 RPM in its stock form. This makes it one of the more powerful naturally aspirated 4-cylinder engines available in the mid-2000s from Honda.
4. Compression Ratio:
   • The K24A2 has a compression ratio of 10.5:1, which contributes to its efficiency and power output. This makes it well-suited for naturally aspirated applications, but it can also handle mild forced induction setups with proper tuning.
5. Forged Internals:
   • The engine comes with relatively strong internals, including forged steel connecting rods and a cast aluminum block, which can handle moderate performance upgrades without the need for major internal modifications.
6. VTEC Cams:
   • The K24A2 is equipped with performance-oriented VTEC camshafts, which optimize airflow and increase performance, particularly at high RPMs. This makes it more powerful than lower variants of the K24 engine, such as the K24A1 (found in CR-Vs and Elements), which focus more on fuel economy and low-end torque.
7. Intake and Exhaust:
   • The K24A2 has a more advanced intake manifold and exhaust system than lower-spec K24 engines. These components are designed to provide better airflow, contributing to the engine’s higher horsepower and torque ratings.

Common Applications and Swaps

The K24A2 is highly sought after for engine swaps, particularly in lightweight Hondas, due to its power potential, availability, and compatibility with other Honda chassis. Some popular applications include:

1. Honda Civic (EG, EK, and EP):
   • Swapping the K24A2 into older Honda Civics (1992-2000 EG, EK, and EP chassis) is a common modification. The engine provides a significant power boost over the stock D-series or B-series engines, and its increased displacement offers better torque, which is ideal for street and track use.
2. Honda Integra/Acura RSX:
   • Enthusiasts often swap the K24A2 into the Acura RSX (DC5), which comes with a K20 engine from the factory. The K24’s increased displacement and torque provide a noticeable performance increase over the K20.
3. Honda S2000:
   • Although the S2000 comes with the high-revving F20C or F22C engine, some owners opt to swap in a K24A2 for more low-end torque and better daily driving characteristics, while still maintaining a high-revving nature when paired with a K20 head (known as a “K24/K20 Frankenstein swap”).

Performance Potential and Tuning

1. Naturally Aspirated Builds:
   • In stock form, the K24A2 is already potent, but it can be tuned to produce more power with bolt-on modifications such as:
     • Cold air intakes
     • Upgraded exhaust systems
     • High-flow headers
     • Upgraded intake manifolds
     • With proper tuning, it’s not uncommon for naturally aspirated K24A2s to reach 230-250 horsepower with these modifications.
2. K24/K20 Frankenstein:
   • A popular modification is the K24/K20 hybrid build, where the K24A2 block is paired with the high-revving K20A2 head from an Acura RSX Type-S or Honda Integra Type R. This setup takes advantage of the K24’s larger displacement and the K20’s ability to rev higher (up to 9,000 RPM), offering a balance of low-end torque and high-end horsepower. With this combination, power outputs of 300+ horsepower (naturally aspirated) are achievable with the right tuning and supporting modifications.
3. Forced Induction:
   • The K24A2 can also handle turbocharging or supercharging with proper internals and tuning. Many K24A2s can safely run 300-400 horsepower with a turbo kit and supporting modifications, such as upgraded pistons, rods, and a more robust fuel system.
4. ECU Tuning:
   • Tuning the ECU with systems like Hondata K-Pro or AEM EMS is essential to unlocking the full potential of the K24A2 engine, especially after adding bolt-ons or performing significant modifications like the K24/K20 hybrid.