Honda K24 Engine Guide: K24A, K24A2, K24Z3, K24Z6 and K24Z7 Compared

If you are shopping for a K24 engine, you already know one thing. There are a lot of versions, and they are not the same. Some are built for daily driving. Some are built for power. Picking the wrong one can cost you time and money.

This guide breaks down every major K24 variant so you know exactly which one fits your car or your build. We will cover specs, which cars use which code, how to read the stamp on your own engine, and what to check before you buy a used unit.

What is the Honda K24 engine?

The K24 is Honda's 2.4L four cylinder engine from the K series family. It uses i-VTEC, which is Honda's system for switching valve timing and lift to balance power and fuel economy. Think of it as one engine with two personalities, calm at low RPM and aggressive up top.

The K24 first showed up in the early 2000s and is still used today. It has an aluminum block, a timing chain instead of a belt, and a reputation for being tough.

K series basics: i-VTEC, timing chain and aluminium block

• i-VTEC: switches cam profiles for efficiency and power
• Timing chain: no scheduled belt replacement like older Hondas
• Aluminum block: lighter weight, better heat handling

Why the K24 became the default Honda swap engine

It is affordable, plentiful, and strong. Builders like that it responds well to bolt-ons and that parts support is huge. For a lot of Honda and Acura owners, it is simply the easiest 2.4L to find and trust.

K24 variants at a glance

Figures come from Honda and Acura service data. Always confirm exact output with your model year since trims vary.

See the K24 engines we have in stock if you already know which code fits your car.

JDM K24 variants

K24A (RAA), Accord, CR-V, Element

This is the original K24. It is a strong, low compression base engine that works well as a direct replacement in the Accord, CR-V, and Element.

K24A2 (RBB), Acura TSX

The TSX version steps things up with higher compression and a hotter cam. This is the one swap builders reach for when they want more power without going forced induction.

K24A3 and other export variants

Some export market versions share the RBB or RAA head but with small tuning differences. Always check the engine code stamp rather than assuming by model name alone.

USDM K24Z variants

K24Z1, CR-V 2007-2009

A refined version of the RAA era engine, tuned more for smooth daily driving than outright power.

K24Z2 and K24Z3, Accord and TSX

The K24Z3 carries the RBB-2 head and is one of the strongest naturally aspirated K24s available for a swap.

K24Z6, CR-V 2010-2014

Built for reliability and fuel economy in a crossover, not for aggressive driving.

K24Z7, Civic Si 2012-2015

The highest compression K24 on this list. It is the enthusiast favorite for a Civic Si build.

Which K24 fits my car?

How to identify the K24 you already have

Where the engine code is stamped

Every K24 has its code stamped into the block near the transmission mount. It is usually a short combination of letters and numbers, and it is the most reliable way to know exactly what you have, even if a previous owner swapped parts around. Our team photographs this stamp on every unit before it ships, so you can match it before you buy instead of guessing from a listing photo.

Reading the cylinder head casting (RAA, RBB, RBB-2)

The head casting number tells you the real story, even if the block code is worn off. RAA is the base head, RBB is the higher output TSX head, and RBB-2 is the updated Accord and TSX head.

Which K24 is best for a swap?

Best for power: high compression heads

If power is the goal, the K24A2, K24Z3, or K24Z7 give you the best starting compression and cam profile.

Best for a daily driver replacement

If you just need your car running again, match the exact code for your model. Don't overthink it.

What else the swap needs

A swap is never just the engine. You will also need:

• A compatible ECU and harness
• Correct engine mounts for your chassis
• A matching transmission if you are changing cars

Nothing here is plug and play unless we say so directly.

K24 vs K20: which should you choose?

The K20 revs higher and feels sportier, especially in the higher trims. The K24 makes more low end torque and is easier to find in good condition. For daily driving, cruising, or a car that also needs to carry weight, the K24 wins on comfort and availability. For a high RPM, track focused build where screaming top end matters more than torque, the K20 has the edge. A lot of builders actually combine the two, using a K20 head on a K24 block, but that is a different project with its own parts list.

Common K24 problems to check before buying

• VTEC solenoid wear causing a rattle on cold start
• Oil consumption on high mileage units, worth checking before you commit
• Timing chain tensioner noise, usually more annoying than serious
• Worn motor mounts, which can feel like an engine problem but often is not

None of these are deal breakers on their own, but they are worth asking about. Always ask for compression numbers and, if possible, a video of the engine running before you buy any used unit online.

Buying a JDM K24: mileage, testing and what ships with the engine

Our JDM K24 engines are imported at typical low mileage for their age and tested before listing. Every used replacement engine carries a 60 day warranty, and performance engines carry a 30 day warranty. Send us your VIN and model year, and we will confirm the exact fitment before you order.

FAQs

How much horsepower does a K24 make?

Depending on the code, a K24 makes between roughly 156 and 205 horsepower from the factory. The K24Z7 and K24A2 sit at the top of that range.

Is the K24 a reliable engine?

Yes, when maintained. It has a strong reputation among Honda and Acura owners for going well past 200,000 miles with basic care.

Can I put a K24 in a Civic?

Yes, this is one of the most popular Honda swaps. You will need the correct mounts, ECU, and harness for your Civic chassis.

What is the difference between K24A and K24Z?

K24A codes are the earlier generation. K24Z codes are the later, updated generation with revised heads and internals for each application.

Does a K24 come with the transmission?

It depends on the listing. Some of our K24 engines ship as a package with the matching transmission. Check the product page or ask us directly.

Conclusion

The right K24 depends on what you are building. A K24A or K24Z1 is fine for a simple daily driver swap. A K24A2, K24Z3, or K24Z7 makes more sense if power matters to you. Match the code, check the head casting, and confirm fitment with your VIN before you buy. Skipping this step is how people end up with an engine that almost fits, which usually costs more to sort out than getting it right the first time. Call us at (407) 412-5888, or contact us to send your VIN and model year, and we will help you find the exact K24 your car needs.