If you’re looking for a reliable and tunable four-cylinder engine, the Honda K24Z5 is a fantastic place to start. This guide covers the complete Honda K24Z5 Engine Specs and Performance to give you a clear picture of what this powerplant offers.
You’ll find this engine in some popular Honda models, and it’s known for its smooth power delivery and strong aftermarket support. Whether you own a car with this engine or are considering a project, understanding its details is key.
Honda K24Z5 Engine Specs and Performance
The K24Z5 is a 2.4-liter, inline-four cylinder engine part of Honda’s renowned K-series family. It’s a direct descendant of earlier K24 engines but with specific refinements for its applications. Primarily, it served in the 2009-2014 Acura TSX and the 2013-2017 Acura ILX.
This engine was designed to provide a great balance of everyday drivability and spirited performance. It features Honda’s i-VTEC system, which adjusts valve timing and lift for efficiency and power. Let’s break down its core technical specifications.
Detailed Technical Specifications
Here are the core specs that define the K24Z5 engine’s architecture and capabilities. These numbers are the foundation of its performance.
* Engine Type: Inline-4 cylinder, naturally aspirated
* Displacement: 2.4 liters (2354 cc)
* Bore x Stroke: 87 mm x 99 mm (3.43 in x 3.90 in)
* Compression Ratio: 10.5:1
* Valvetrain: DOHC, 16-valve, i-VTEC (Variable Valve Timing and Lift Electronic Control)
* Fuel System: Multi-Point Fuel Injection (PGM-FI)
* Block Material: Aluminum alloy with cast-in iron cylinder liners
* Cylinder Head Material: Aluminum alloy
* Recommended Fuel: 91 Octane Premium (for optimal performance)
* Oil Capacity: Approximately 4.5 quarts (with filter)
The engine’s undersquare design (bore smaller than stroke) contributes to its strong low-end and mid-range torque. This makes it feel very responsive in daily driving situations without needing to rev it extremely high.
Power Output and Performance Figures
The K24Z5 was tuned differently depending on the vehicle it was placed in. The power outputs are respectable for a naturally aspirated engine of its size.
* Acura TSX (2009-2014): 201 horsepower @ 7000 RPM / 170 lb-ft of torque @ 4400 RPM
* Acura ILX (2013-2017): 201 horsepower @ 7000 RPM / 170 lb-ft of torque @ 4400 RPM
These figures provided a smooth, linear power band. The engine pulls strongly from around 3000 RPM and continues to build power until its redline, which is typically at 7100 RPM. The power delivery is predictable and makes the car easy to drive fast.
Key Engine Components and Design
The K24Z5’s design incorporates several hallmark Honda technologies that contribute to its durability and performance. Understanding these parts helps you see why it’s so well-regarded.
The i-VTEC System
This is the heart of the engine’s character. The system combines VTEC (Variable Valve Timing and Lift Electronic Control) with VTC (Variable Timing Control).
1. VTC continuously adjusts the intake camshaft timing over a wide range.
2. VTEC switches to a high-lift, longer-duration cam profile at higher RPMs.
3. The result is excellent low-end torque and fuel economy, with a strong top-end power rush.
The transition is noticeable and gives the engine a fun, engaging feel when you push it.
Cylinder Head and Valvetrain
The K24Z5 uses the popular RBB cylinder head casting. This head has excellent flow characteristics right out of the box. The valvetrain is robust, using rocker arms that engage the high-lift cam lobes when VTEC activates. Proper maintenance of this system is crucial for long-term reliability.
Block and Rotating Assembly
The aluminum block is lightweight and strong. The crankshaft and connecting rods are forged from high-strength steel, making the bottom end quite durable for a stock engine. The pistons are cast aluminum and are designed for the 10.5:1 compression ratio. This robust internals are a big reason why the K24Z5 handles modifications so well.
Common Applications and Model Years
Knowing which cars used this engine is important for sourcing parts or buying a vehicle.
* Acura TSX (Sedan): Model years 2009, 2010, 2011, 2012, 2013, 2014.
* Acura ILX (Sedan): Model years 2013, 2014, 2015, 2016, 2017.
It’s important to note that not all TSX or ILX models from these years have the K24Z5. Some, especially the ILX, came with other engines like the K24Z7 or an R20. Always check the engine bay label or VIN to be certain.
Performance Potential and Modifications
The K24Z5 is a favorite among tuners because it responds very well to bolt-on modifications. The strong internals provide a solid platform for more power. Here’s a typical progression for modifying this engine.
Stage 1: Basic Bolt-Ons
These mods improve airflow and free up horsepower without opening the engine.
* Cold Air Intake (CAI): Reduces intake air temperature and improves throttle response.
* Performance Exhaust Header: Replaces the restrictive factory manifold for better exhaust flow.
* Cat-Back Exhaust System: Further reduces backpressure and improves sound.
* Engine Tune: A custom ECU reflash (using Hondata or KTuner) is essential to maximize gains from bolt-ons and adjust parameters like VTEC engagement.
With these simple mods, you can expect gains of 20-30 horsepower at the wheels, making the engine feel much more lively.
Stage 2: Advanced NA (Naturally Aspirated) Build
For serious all-motor power, builders look inside the engine.
1. High-Compression Pistons: Raise compression to 12.5:1 or higher for more power per stroke.
2. Performance Camshafts: Aggressive cams increase valve lift and duration for better high-RPM breathing.
3. Ported Cylinder Head: Smoothing and enlarging the intake/exhaust ports improves airflow.
4. Upgraded Valvetrain: Stiffer springs and retainers are needed to handle high-RPM operation with bigger cams.
5. Standalone ECU: For precise control over fuel, ignition, and VTEC with radical parts.
A well-built all-motor K24Z5 can produce over 250 horsepower at the wheels, but it requires significant investment and expertise.
Stage 3: Forced Induction
This is the most common path for big power. Turbocharging or supercharging the K24Z5 is very effective.
* Turbo Kit: Includes turbocharger, manifold, intercooler, piping, and necessary fittings. Requires careful tuning to manage boost and fuel.
* Supercharger Kit: Often a centrifugal or roots-type blower that provides linear, instant boost. Can be simpler to install in some cases.
* Supporting Mods: You will need larger fuel injectors, a high-flow fuel pump, and a strong clutch. The stock block can often handle moderate boost (300-350 whp) reliably, but for higher levels, forged internals are recommended.
With a conservative turbo setup, 350-400 wheel horsepower is very achievable, completely transforming the car’s performance.
Reliability and Common Issues
The K24Z5 is generally a very reliable engine when maintained properly. However, like any mechanical item, it has a few known areas to watch.
* VTEC Solenoid Gasket: This small gasket can leak oil over time. It’s a cheap and easy fix.
* Valve Cover Gasket: Another common seepage point as the engine ages. Replacement is straightforward.
* Engine Mounts: The hydraulic engine mounts, especially the rear one, can wear out and cause vibration.
* Oil Consumption: Some engines may consume a small amount of oil, especially at higher mileage. Regular checks are advised.
* Timing Chain Tensioner: While the chain itself is reliable, the automatic tensioner can sometimes fail. Listen for rattling on startup.
Following the factory maintenance schedule for oil changes (using quality 0W-20 or 5W-20 oil), spark plugs, and coolant is the best way to ensure a long engine life. These engines can easily last over 200,000 miles with care.
Maintenance Schedule Overview
Sticking to a routine is key for longevity. Here are the critical service intervals.
* Engine Oil & Filter: Every 5,000-7,500 miles (synthetic recommended).
* Spark Plugs: Replace every 100,000 miles (Iridium-tipped).
* Engine Coolant: Replace every 60,000 miles or 5 years.
* Timing Chain Inspection: Check for stretch or tensioner issues at major services (100k+ miles). It’s not a routine replacement item like a belt.
* Valve Clearance Adjustment: Check and adjust if necessary every 100,000 miles. This is important for smooth running and power.
Keeping up with these services will prevent most major problems and keep the engine running smoothly.
FAQ Section
What is the difference between the K24Z5 and the K24Z7?
The K24Z7, found in later ILX models, has a lower compression ratio (10.0:1) and different tuning for regular fuel. It makes slightly less power (around 185 hp) and is designed for maximum fuel economy.
Can you swap a K24Z5 into an older Honda?
Yes, K-series swaps are extremely popular. The K24Z5 can be swapped into cars like the Honda Civic, Integra, or CR-X. It requires swap mounts, wiring harness adaptations, and often an aftermarket ECU. It’s a great way to add modern power to a lightweight classic.
Is the K24Z5 a good engine for turbocharging?
Absolutely. Its strong internals make it one of the best K24 variants for turbo applications. With proper tuning and supporting mods, it can handle significant boost and make big power reliably.
What kind of fuel mileage can I expect from a K24Z5?
In a TSX or ILX, you can expect around 22-24 MPG in combined city/highway driving. On the highway, it’s possible to see 30-32 MPG with gentle driving. Of course, modifications and driving style greatly affect these numbers.
How does the K24Z5 compare to the famous K20A2?
The K20A2 (from the RSX Type-S) is a 2.0L high-revving engine. The K24Z5 has more displacement, giving it superior low-end and mid-range torque, making it feel stronger in daily driving. The K20A2 loves to rev higher and may have a slight edge in peak horsepower per liter, but the K24Z5 is often considered a more flexible and torquier street engine.
The Honda K24Z5 engine stands as a testament to Honda’s engineering philosophy: efficient, reliable, and fun. Its blend of solid power, tunability, and durability has earned it a dedicated following. Whether you keep it stock, add a few bolt-ons, or build it for serious power, it’s a platform that rewards enthusiasm and proper care. By understanding its specs and characteristics, you can make the most of this excellent powerplant for years to come.