Best Miata Engine Swaps: The Complete Guide

A miata engine swap is one of the most popular ways to transform a car that already handles great into something that also has the power to match. The Miata has always been loved for its chassis balance and steering feel, but the factory engine was never built to be a straight line monster. Swapping it changes that completely. This guide walks through the most popular swap options, what they cost, how hard they are, and which one actually fits your goals.

Why Swap Your Miata's Engine?

Most people who swap their Miata are not doing it because the factory engine is unreliable. They are doing it because they want more power without giving up the chassis that made them fall in love with the car in the first place.

The Miata's biggest strength is its light weight and near perfect fifty fifty weight distribution. A swap changes that balance depending on what you put in, so the goal for most builders is finding an engine that adds power without ruining what makes the car special to drive.

There are a few common reasons people go this route:

• The factory engine is aging out and needs a rebuild anyway, so why not upgrade at the same time

• They want significantly more power for track days or drag builds

• They want a more modern, easier to tune platform under the hood

• They simply want a different driving character than the stock motor offers

Whatever the reason, a miata engine swap is a serious project, not a weekend bolt on. Planning matters more here than almost any other part of the build.

Before you start pricing parts, it helps to sit down and honestly answer what you want the finished car to feel like. A swap that maximizes horsepower is not the same project as a swap that keeps the car light and playful. Both are valid goals, but they lead you toward very different engines, and mixing up your priorities halfway through a build is how projects end up half finished in a garage for years.

Miata Swap Options at a Glance

Here is a quick snapshot of the most popular swaps before we go deeper into each one.

Costs vary a lot depending on whether you are buying used parts, doing labor yourself, and how far you push the build. Treat these as ballpark figures, not exact quotes.

BP 1.8L + 6-Speed, The OEM+ Upgrade

If your Miata currently has the smaller 1.6 liter engine, upgrading to the later BP 1.8 liter is one of the simplest and most cost effective swaps available. This is often considered a na miata engine swap done right, since it keeps things naturally aspirated and stays true to the car's original character.

The BP swap gives you more displacement, more torque, and access to the later 6-speed transmission, which is a big quality of life upgrade over the earlier 5-speeds. Because the BP was designed for later Miatas, the swap is relatively straightforward compared to dropping in an engine that was never meant for this chassis.

This is the swap most people recommend if your goal is a slightly stronger, more refined version of the Miata experience rather than a dramatic power increase. It keeps the car feeling like a Miata, just a bit sharper.

It is also a great starting point for anyone new to engine swaps in general. Because the BP was designed to live in a Miata chassis from the factory, you skip a lot of the custom mount and wiring headaches that come with dropping in an engine from a completely different platform. That makes it a solid first project before moving on to something more ambitious down the line.

K-Swap (K24), The Reliable Power Route

For builders who want serious power while keeping things naturally aspirated, a miata k swap using Honda's K24 engine has become one of the most respected options in the community.

The K24 is known for being tough, revving high, and responding extremely well to bolt on modifications. A k24 swap miata build typically lands somewhere between 200 and 240 horsepower depending on the specific K24 variant and supporting mods, which is a massive jump over stock.

Why builders love this swap:

• The K24 is a proven, reliable Honda engine with a huge aftermarket

• It revs high and pulls hard, matching the Miata's playful character

• Parts and tuning knowledge are widely available thanks to Honda's popularity

The tradeoff is complexity. This is not a bolt in swap. You are dealing with custom mounts, wiring, and often a different transmission setup. It takes real fabrication skill or a shop that specializes in these builds, but the end result is one of the most balanced high power Miata builds you can do.

Weight is a big reason this swap has become so popular. The K24 is not a heavy engine, so it does not throw off the Miata's balance nearly as much as a V8 does. You get a huge power increase while keeping most of the nimble, tossable feel that made you want a Miata in the first place. That balance between power and character is exactly why this swap keeps growing in popularity year after year.

LS V8 Swap, Maximum Power

If raw power is the priority, the miata ls swap is the answer most builders eventually land on. Dropping a Chevy LS V8 into a Miata sounds extreme, and it kind of is, but the aftermarket support for this swap has grown massively over the years.

LS engines are compact for a V8, relatively light thanks to their aluminum block, and insanely tunable. A basic LS swap can put you well over 300 horsepower, with built versions pushing far past 400 without much trouble.

Things to know before committing to an LS swap:

• Weight distribution shifts more than with a four cylinder swap, so suspension and chassis upgrades are usually necessary

• Cooling system upgrades are a must, since V8 power output generates a lot more heat

• Wiring is a bigger job here, though standalone harness kits have made this much easier than it used to be

• This swap changes the character of the car significantly, from nimble roadster to genuine muscle car in a small package

This is the swap for builders chasing raw straight line performance and are willing to accept a completely different driving feel in exchange.

It is worth being honest with yourself about maintenance too. A properly done LS swap can be shockingly reliable, since LS engines have a well earned reputation for durability. But properly done is the key phrase there. A rushed install with cut corners on cooling or wiring will cause way more problems than the engine itself ever would. Take the time to do it right, or work with a shop that has done several of these builds before.

Other Popular Swaps

Beyond the big three above, a few other swaps have earned loyal followings in the Miata community.

• 1JZ swap: Toyota's legendary turbo inline six brings smooth power delivery and strong tuning potential, popular with drift builders

• 13B rotary swap: for those chasing something completely different, a rotary swap brings high revving power and a totally unique sound, though it comes with the maintenance quirks rotaries are known for

• Honda F or H-series: less common than the K24, but still used by builders looking for a different Honda power option

Each of these brings its own personality to the build. If you already have experience with one of these engine families, sticking with what you know can make the swap process a lot smoother.

These lesser known swaps tend to attract builders who already know exactly what they want out of the finished car. If you are still deciding between options, the BP, K24, and LS swaps remain the safest bets simply because there is so much documented experience and support already out there in the community. That existing knowledge base makes troubleshooting far easier when something inevitably needs adjusting.

Cost, Difficulty & What to Budget

When people ask about the best miata engine swap, the honest answer is that it depends entirely on your budget and goals. Here is a general breakdown of what to expect.

• Budget builds: the BP 1.8 swap is the most affordable route, especially if you already own a donor car or can source used parts

• Mid range builds: K-swaps land in a middle ground, more expensive than the BP but far less than a full LS build once you factor in supporting mods

• High budget builds: LS and 1JZ swaps require the most investment once you add cooling, wiring, transmission, and tuning costs on top of the engine itself

Do not forget to budget for the extras. Motor mounts, wiring harnesses, exhaust work, cooling upgrades, and professional tuning all add up fast. Most builders end up spending more on supporting parts and labor than they do on the engine itself.

It also pays to think about resale and long term ownership before you commit. A well documented swap with quality parts and professional tuning holds its value far better than a rushed budget build, even if the horsepower numbers look similar on paper. Buyers down the line will pay more for peace of mind, and you will enjoy the car more in the meantime knowing it was built right the first time.

Which Miata Swap Is Right for You?

Here is a simple way to think about your decision based on what actually matters most to you.

Go with the BP 1.8 swap if:

• You want a mild, reliable upgrade that keeps the car's original character

• Budget is a top priority

• You want a straightforward installation without major fabrication

Go with the K24 swap if:

• You want strong naturally aspirated power with proven Honda reliability

• You are comfortable with a more complex, semi custom install

• You want your Miata to still feel high revving and playful, just faster

Go with the LS V8 swap if:

• Maximum power is the goal, straight line performance above all else

• You are willing to accept a different driving character in exchange for serious horsepower

• You have the budget for cooling, wiring, and chassis upgrades to match the new power

Whatever direction you choose, a well planned swap can turn a Miata from a fun little roadster into something genuinely special, without losing the qualities that made you want one in the first place.

Take the time to research your specific chassis year too, since mounting points and electronics vary between generations. What works cleanly on one Miata year might need extra fabrication on another. A little extra research before you buy parts can save you a lot of frustration once the build is actually underway.

Ready to Start Your Swap?

Check out our Miata BP engine and 6-speed package for a straightforward power upgrade, or browse our Honda K-Series collection if you are ready to build a K24 swap. Every engine we source is tested and documented, so you know exactly what you are working with before the build even starts.