The Ultimate K-Swap Installation Guide

Welcome back to our blog; this guide aims to help you on the journey to K-Swap your car. We run through everything from OEM to Aftermarket parts and the best engines for a K-Swap.

We will review brands we recommend, tips and tricks, OEM parts, optional parts, and much more. By the end, you will know everything there is to know about K-Swaps!

What Does The Term K-Swap Mean?

The Term "K-Swap" is used to describe swapping a Honda K-Series engine into a chassis that doesn't come with it from the factory.

The most common cars for this are Honda Civic EG 92-95, Honda Civic EK 96-00 and Honda Integra DC2 96-01. Still, you can K-Swap virtually any car with enough willpower!

The most commonly used engine in a K-Swap is the K20a2 from a Honda Civic EP3 Type R or the K20A from a Honda Integra DC5 Type R.

These engines are the most common because they are coming down in price and are the most tuneable from this era.

The aftermarket car parts world is a treasure trove for car enthusiasts, offering parts that can boost your car's horsepower at a reasonable price point.

Furthermore, aftermarket manufacturers have not only fixed many factory problems with their solutions but also enhanced the driving experience, ensuring you get the best out of your car.

How Much Does A K-Swap Cost?

The cost of this swap depends on the parts you decide to use. This guide will list all the OEM and aftermarket parts you need. In most cases, you can use OEM parts to keep the budget down, but this will be impossible in some cases (such as wiring conversion loom).

As OEM factory parts naturally wear over time, the use of brand-new products is strongly recommended for a reliable K-Swap. This emphasis on reliability will give you the peace of mind that your swap is built to last.

The most common starting point would be either with an EP3 or DC5 donor car to swap as much out of it as possible, or at least start with the basics on this list and expand upon them.

OEM Parts List

You will need these parts from a K-Series car at the bare minimum as a starting point. The list needs to include the following:

• Engine
• Gearbox
• Starter Motor
• Alternator
• All Sensors
• Engine Loom
• Charge Harness

In an ideal world, you can take as much as you can from the donor car, and all the parts above are the bare minimum you can get away with taking from the K-Series car.

The parts that are optional to get second-hand, but if you're on a budget, are worth getting are:

• Dc5 Shifter
• Dc5 Shifter Cables
• Ecu

Later in this guide, we will review the aftermarket alternatives to these three options to determine whether you think the upgrade is worth it.

If you're using a Honda Civic Ek chassis, you would need a Honda Civic EG or Honda Integra DC2 subframe (and bolts as they differ), front lower control arms and a steering rack.

It would be best to use an EG subframe to move the engine back slightly in the engine bay, giving more clearance for the radiator and air conditioning compressor.

Also, by moving everything back, the driveshafts sit at a much straighter angle than if you were using an EK subframe.

Aftermarket Parts List

This section covers all the aftermarket parts needed to make the K-Swap happen.

To keep the guide consistent throughout, we will use the Honda Civic EK as our base point, but all of these parts will be used in most cases regardless of which chassis you plan to swap into.

There are some direct fitment swap parts for specific cars, such as the hasport conversion looms, but if you are swapping into something such as a Nissan Silvia S13, you would need a custom loom made here.

Engine Mounts

The first thing on the list of aftermarket parts would be engine mounts. Because your OEM mounts will be designed to fit your engine and chassis from the factory, you have to use specific K-swap engine mounts.

These K-Swap mount kits are designed to fit the OEM mounting locations on your chassis and the K-Series engine and gearbox for a stress-free bolt-in option. There are a few options here, such as:

• Hasport
• Innovative

Engine Mount Urethane Rating

There are a few varying factors here. The first is the urethane rating of the engine mount bushes. Generally, most people decide which bush to go with based on what they will use the car for.

These are the different ratings of bushings to choose from, but they will vary slightly from brand to brand. We will use Hasport here as a point of reference:

• U62a (Street)
• U70a (Race)
• U88a (Extreme)
• U94a (More Extreme)
• Solid 6061 (Extreme, Race Only)

Once you've picked the bush, it's time to choose the brand and fitment you prefer.

Hasport, for example, makes a few variations for the Civic EK; if you use a k20a2 engine and gearbox and want a 62a bush for the street, you'd use their HAS-EKK2-62A kit, which is specifically designed for use with the Civic EG subframe.

There are also options for k24 transmissions, so you must match your engine mounts to this for fitment purposes.

K-Swap Short Shifter

If you go for an OEM shifter setup, you can skip this step and the shifter cable step; if not, let's go into what you'll need.

The two main reasons for buying a brand-new shifter are that your OEM one is worn or you want to shorten the throw.

Also, some of the shifters on the market look beautiful and are always the finishing touch to your interior.

Aftermarket shifters, such as the Hybrid Racing V3 DC5 short shifter, feature an adjustable throw, from 10% to 50% quicker than stock, and are also available in dust red or dust black.

Because of this decrease in shift distance, your shifts will feel much crisper and more positive than those of the stock shifter.

They also have a flush, no-cut bolt-in option that bolts underneath the tunnel, allowing you to retain the stock centre console and achieve an OEM+ look.

The K-Tuned short shifter operates similarly to the hybrid or OEM shifter, so the choice between them ultimately comes down to personal preference. Your unique driving style and car modification goals should guide your decision.

Shifter Base Plate

As the Honda Civic EG/EK and the Honda Integra DC2 all used shifter linkages from the factory and not shift cables, you will have a hole in the exhaust tunnel where the shifter used to come through. You will use shifter cables when going to K-Swap, so there will be an unused hole in the chassis.

Hybrid Racing and K-Tuned both have manufactured base plates that bolt to your tunnel, blocking off this hole and mounting the shifter in the process, making for a much easier installation.

Once installed, the shifter will bolt directly on top of this plate, eliminating all of the guesswork. The Hybrid Racing base plates even come with a rubber seal to close the hole underneath to stop fumes from entering the car.

They also include the necessary hardware to make this a complete bolt-in option.

K-Swap Shifter Cables

The next part on the list would be the K-Swap shifter cables. For the cables, you must use Honda Integra DC5 specification cables to bolt to the shifter correctly and the gearbox (even using the Hybrid Racing no-cut shifter).

There are a few good options over stock here; as mentioned in the shifter section, Hybrid Racing and K-Tuned would be the best option here.

They both offer bolt-in direct replacement cables and utilise spherical bearings, unlike OEM rubber, which makes your gear changes feel tighter over stock.

The biggest complaint of stock cables is that they feel "sloppy" to use, and spherical ends completely solve this issue.

Recently Hybrid Racing has released a revised version of their DC5 shifter cables which are slightly shorter, making them currently the best option for K-Swap shifter cables.

Shifter Cable Grommet

When installing the Shifter cables into a K-Swap car, generally, you will not have a hole for the cables as the shift linkage used to be underneath the vehicle.

You must drill a hole in the firewall for the cables to pass through. The cut hole is usually underneath the heater pipes, but you are left with a large ugly hole, and where K-Tuned comes in.

They developed a shifter cable grommet to allow both cables to run through the firewall without risking the cables rubbing through the metal.

Installation is simple; drill the correct hole size, bolt the plate in all four corners, and you're done!

Optional Shifter Parts

Before we move on to the next part, it's worth mentioning some products which will make your driving experience better. K-Series detent springs are a popular option and usually offer up to an 80% stiffer spring rate than stock.

This stiffer spring aids the gear selector fork by adding more pressure, making your shifting feel sharper.

The best current options for these would be the Hybrid Racing and Speedfactory Racing variations, as they are both well-tested.

We even use the Speedfactory Racing detent springs in our own B-AWD Civic, and they made a massive difference to the feel of the gear changes.

The last optional upgrade worth looking at is a shifter spring upgrade. If you were going to buy a brand new shifter, such as the Hybrid Racing DC5 V3, this would already come with a stiff spring, but if you're looking to upgrade OEM or an older shifter, then this would be the way to go.

Speedfactory Racing heavy-duty K-Series shifter springs are up to 200% stiffer than stock, which will centre the shifter with more force and improve shift accuracy.

K-Swap Driveshafts

Now onto the next step, driveshafts. Your OEM B/D series driveshafts were made to be the correct length and spline for the B/D-Series, but will not fit the K-Series.

Because of this, you will need specific K-Swap driveshafts. A few options are on the market, but we generally go towards Hasport for these.

They make specific Honda Civic Ek K-Swap driveshafts to bolt in and fit into the gearbox and hub with the correct splines and length, making this step hassle-free.

If you use something other than a Honda Civic EK as your chassis, then Hasport also manufactures several variations of Honda K-Swap driveshafts.

Check out their catalogue to see if they have the correct swap driveshafts for you.

If you want to save a bit of money, there is also an option of using K-Series driveshafts with B-Series outer CV joints for Civic EK, but if you're going down this route, it would be worth researching to find out exactly what would fit your chassis.

Clutch Line

The OEM clutch line in a Honda Civic EK/EG or Integra DC2 was designed for a D/Bseries, so the line does not fit a K-series slave cylinder.

Because of this, you will need to consider upgrading your clutch line to a K-Swap line. These lines have the correct thread at the master cylinder and slave cylinder and are slightly longer to fit perfectly into a K-Swap.

Also, over time, the stock clutch line can become perished, so it would be worth upgrading to a braided stainless steel option.

The two leading brands that manufacture K-Swap clutch lines would be Hybrid Racing and K-Tuned, so it would be down to your preference on which one you choose.

Alternatively, suppose you are K-Swapping into another chassis.

You may have to manufacture a custom clutch line, but we can assist with that as we work closely with Hel Performance, who can create any custom length, thread, and colour you want.

Throttle Cable

The factory Honda throttle cables are now becoming worn and stretched over time, so it's worth upgrading to a new option.

Hybrid Racing manufactures a perfect-length K-Swap cable for a perfect fit and to reduce slack in your throttle pedal.

Their throttle cable connects directly to your throttle body and pedal and even has a handy clip for holding it to the bulkhead.

K-Swap Exhaust Manifold

Now that you have sorted out how to mount the engine and the transmission setup, the exhaust manifold is the next thing to look at.

The stock K-Series exhaust manifold will not fit due to now using a different subframe, so for clearance reasons, you will need to look at an aftermarket option such as Tegiwa, K-Tuned or Skunk2.

All three of these brands make specific K-Swap exhaust manifolds that will fit without having to notch your subframe and will bolt directly to your existing catalytic convertor.

The K-Swap manifolds generally have a bigger bore than stock (typically 2.5") which will flow more than the stock manifold and feature equal-length runners for optimal flow.

If you aim for the most power possible, then the K-Tuned big tube manifold would be the way to go, as it features a large 3" exit, currently the most oversized bore on the market.

A 3" exit manifold, matched with a 3" exhaust, will be the highest possible flow you can achieve out of the box without getting a custom exhaust and manifold made.

K-Swap Air Intake

Due to the B/D Series engines found in the 90's era Hondas having the throttle body at the back of the engine bay and the K-Series towards the front, you cannot use your existing air intake.

Because of this, a few companies have designed air intake systems specifically for the K-Swap Honda chassis.

As we know from tuning over the years, the colder the air going into the engine, the more power you will make.

This would make a Hybrid Racing or K-Tuned cold air intake the best option here as not only will it increase performance, but it also fits perfectly into a Honda Civic EG/EK and Integra Dc2 chassis.

Which one you choose would depend on budget, looks and manifold choice.

K-tuned has a few options depending on your inlet manifold choices, such as with or without velocity stack and 3" or 3.5" to cater for most setups.

Hybrid Racing have gone with one cold air intake option, a velocity stack version, with a total 3" diameter but a complete silicone construction for reduced intake temperatures.

Wiring Conversion Harness

You will have an ECU, engine loom, and interior loom in your stock wiring setup.

From the factory, the 3 of these are plugged together to send signals to each part, such as engine to dash cluster or engine to ECU.

Because you are now fitting a K-Series engine and ECU, you will need a harness to connect to your interior loom to make the factory gauge cluster work.

Again like most of the specific K-Swap parts on this list, Hybrid Racing and K-Tuned have options for a completely plug-and-play setup.

In this example, there is a specific Hybrid Racing Honda Civic Ek 96-98 loom and K-tuned alternative, both excellent options here.

Suppose you are swapping into a different chassis, you can either use a universal loom, or you may have to consult a wiring specialist on this step if you want to use your factory cluster.

Alternatively can opt for something like a digital dashboard and CAN setup, but we will cover that in another guide.

Engine Control Unit (ECU)

The engine control unit, or ECU for short, is the circuit board that keeps your brand-new K-Swap running. The ECU controls everything in the engine, from spark to fuel, and with a combination of all the sensors, everything runs perfectly.

If you have decided to keep the stock ECU, you can move on to the immobiliser bypass section, which you will need, and If not, we will run through the various ECU options you can choose from.

The most popular option would be a K-Pro ECU made by Hondata and essentially a board that bolts into the stock ecu, converting it to be fully reprogrammable.

With this fitted, you can take it to your tuner and get the most out of your brand-new setup, with extra added features, such as launch control.

If you need more controllability than a K-Pro can handle, Haltech is one of the best standalone options for engine management.

The most common Haltech to be used on a K-Swap would be the Elite 1500 range, and it can also come with an EP3/DC5 jumper harness to allow it to plug directly into your loom without the need for any custom wiring.

Another massive advantage of using a Haltech dash is that you can link to one of their digital dashes.

Advantages of using a standalone ECU with a digital dash include:

• Swapping your gauge cluster to their IC-7 digital dash.
• Showing you every engine sensor in real-time.
• Even displaying warnings for conditions you can choose to set.

Again, like everything in this guide, this step will depend on your budget and what you use the car for. If you are still determining which ECU to go for, drop us a comment below, or reach out to us for advice.

Immobiliser Bypass

If you choose the stock Honda K-Series ECU, you must run an immobiliser bypass unit.

Because the stock ecu is designed to run with an immobiliser matched to the key, and as there won't be one detected in the system, you will not be able to use the ECU, and it will also throw up an engine management code.

An immobiliser bypass will fix both problems and is easy to install with just four wires. This box completely bypasses the immobiliser system meaning you can start the car without issues by wiring into the system's code signal wire.

There are two options here: the Hybrid Racing unit or K-Tuned, and they are both excellent choices.

One thing to note is that they only work on specific codes of ECU, so it's worth checking your ECU for this before purchasing.

For reference, they usually work with ECU codes:
PLM, PLR, PND, PNF, PRA, PRB, and PPA.

Although it's worth checking the product descriptions of each to make sure it's compatible with your exact ECU.

K-Swap Radiator, Hoses and Brackets

The stock Honda radiators are generally on the driver's side, but for a K-Swap, you ideally need them on the passenger side.

The stock K-Series hoses are on this side, and the rest of the system is designed around this, including the thermostat housing.

The aftermarket radiators are designed with a modified bottom coolant hose port, pointing to the correct way if installed on the passenger side.

The fact aftermarket radiators are designed like this saves a lot of headaches and will be a direct fit with K-Swap radiator hoses.

There are various options to choose from when it comes to a K-Swap radiator.

Do you want a half-size or full-size radiator?

Both options are available, but our usual go-to is the half size as they are neater, and unless you are going with a high-power turbo or high-compression build, it will cool enough for the street.

Currently, many brands manufacture a specific K-Swap radiator, such as:

• Tegiwa
• Hybrid Racing
• Mishimoto
• K-Tuned

It is your choice which one to choose, as they are all excellent options at different prices.

K-Swap Radiator Hoses

You will need to run a set of specific K-Swap radiator hoses to counter the radiator swapping sides. There are good options here, as all the K-Swap radiator hoses share the exact fitment.

The only difference would be the brand's colour scheme you choose to match your engine bay.

If you went with a full-length or half radiator, you must get the correct swap hoses to match this.

To learn how to install these, head over to our how to install silicone hoses guide.

Coolant Temperature Sensor and Fan Switch

As the stock Honda Civic Ep3 and Integra Dc5 house their fan switch on the radiator, you will also need another option.

Luckily, some of the K-Swap radiators come with ports for the fan switch, making this much more accessible. Still, if they do not, you can use a radiator hose insert, such as the Tegiwa version, which houses the fan switch and coolant temperature sensor.

If your aftermarket radiator has a fan switch port, you need to mount the coolant temperature sensor.

Hybrid Racing make a coolant temperature sensor adapter which you can use to utilise your B/D-Series sensor, which is required in some cases, as some of the older gauge clusters cannot understand some of the data from the K-Series ECU.

Either way would work; it depends on which radiator setup you choose and whether you want to run a hose adapter inline.

Radiator Relocation Bracket Kit

Most people cut off the drivers' radiator mounting brackets and weld them to the passenger side.

Although this does work and is a free option, there are now specifically designed kits which will make your life easier and installation much neater.

K-Tuned manufacture a complete bolt-in radiator relocation kit, including brand-new rubbers and radiator stays. This kit is generally the neatest and most reliable option when fitting your brand-new radiator.

Slim Spal Radiator Fan

There is no point in going through all of this to have cooling issues further down the line. This is where SPAL Automotive comes into the equation. They offer sizes ranging from 3/75" up to 15", although 10"-12" is the most common for this swap.

They also have a range of motor sizes to allow for clearance, as the K-Series will sit closer to the radiator than a B/D-Series.

Spal Automotive would be our only recommendation here as they are the most reliable fans on the market, hence why Speedfactory Racing uses them in their drag spec radiators!

Swivel Neck Thermostat Housing

The last thing to consider on the coolant side of your project is the thermostat housing.

Quite often, the OEM plastic housings become brittle over time and, depending on the location of your radiator, may not 100% line up with your K-Swap coolant hoses.

A fully adjustable swivel neck thermostat housing will be the answer if true.

For this, we would always go towards T7Design as they are 3d scanned to perfectly fit first time, and use OEM thermostats so that they will operate the same as the factory system.

They also offer an optional fan switch port, another answer to the fan switch relocation problem.

The fact that they are 360-degree adjustable, available in black or raw, and can convert to AN16 if needed is a huge bonus!

K-Swap Fuel Rail

The older Honda systems, such as the EP3 and DC5, use a non-return fuel system, but this is not very efficient and will not allow you to supply fuel for your new swap adequately.

If you have an EP3 or DC5 and are struggling with the non-return system, have a read through our guide on how to build an Ep3 fuel return system!

Anyway, back to the K-Swap goodness.

The other advantage of going with a fuel rail such as the Hybrid Racing-specific K-Swap version is that they give you the option of running a centre feed rather than out of the side to keep the line tucked and the neatest it can be.

As you already have to eliminate the OEM K-Series hardlines, you're better off going for a complete AN line system to build exactly how you want to.

There is much more scope with an aftermarket rail, and most of them feature orb06 or orb08 ports to allow for a more considerable flow volume than stock and simplify building the fuel system.

Fuel Pressure Regulator

The next thing on the fuel-related list would be a fuel pressure regulator.

A few options are available, but the best way to choose this is to match the ports to your fuel rail and lines to ensure you don't have any step-ups or downs in the system to allow for the most significant amount of flow possible.

For example, if you chose a K-Swap Hybrid Racing fuel rail with AN06 male fittings out of the rail, you should match this to an AN06 fuel pressure regulator.

Using AN06 will make everything much easier to install and removes the need for adapters.

To learn about AN fittings and the best way to use them, head over to our AN fitting blog, where we explain all this in depth.

Fuel Line Kit

Now you've got your fuel rail and fuel pressure regulator, it's time to choose the fuel lines.

We briefly mentioned this above, but a few things are worth pointing out. Firstly the type of fuel hose you use would depend on the fuel you are planning to run.

If it's only pump fuel, then a push-on or braided rubber hose would be fine, but if you're going for race fuel or anything higher octane than pump fuel, you would need to use braided PTFE hose.

Most of our customers are moving towards using PTFE anyway for futureproofing, as the only downside is that it isn't as flexible as rubber-lined hose but doesn't degrade.

If you want to avoid building your line and want an off-the-shelf kit, then Hybrid Racing make a few direct bolt-on kits to allow you to use your OEM fuel filter setup.

They also make a tucked fuel line kit that includes a filter, which would be the best option if you wanted to tuck as many of the lines as possible.

Optional K-Swap Parts

All the parts in this next section are optional, and only quality-of-life improvements or kits to save space in the engine bay.

These won't stop the K-Swap from working, but for some people are hugely vital whether it's being used as a daily or a full race car.

There are a few advantages of running some of these kits, such as the alternator relocation power steering/air conditioning delete kit, which will allow for larger inlet manifolds and to save space.

Also, an electric water pump conversion kit removes the stock water pump in favour of a pump which can be controlled via the ECU or a separate controller to allow complete control over your flow rate.

The list we would recommend looking at for optional K-Swap parts would be:

• Air Conditioning/Power Steering Delete Kit
• K-Swap Air Conditioning Kit
• K-Swap Power Steering
• Electric Water Pump Kit

Checklist Before Starting Up

Finally, we are onto our last section, which would be things to check and ensure are working correctly. Checking for problems is the most crucial step, as doing something like accidentally missing engine oil could be catastrophic.

The list we would recommend checking or replacing as a starting point is as follows :

• Complete nut and bolt check
• Put in fresh engine oil
• Change the oil filter
• Put in fresh gearbox oil
• Install brand-new spark plugs
• Install a new fuel filter
• Check all electrical work such as grounds/ terminals etc

Once you've checked as much as possible, you are ready to start it up and enjoy your brand-new K-Swap!

Conclusion

We've been through all the parts you'd need to complete a K-Swap conversion from start to finish. You can now find all the products you need confidently without guessing what will fit or what to use.

Be sure to check out some of our other articles for help with things such as AN fitting assembly, how to install titanium intake exhaust studs, or the last guide we published, a start-to-finish B/K Series turbo conversion!

Please let us know in the comments below if this guide helped you, and if you still need any help or advice regarding K-Swaps or any parts or brands we've mentioned in this article, please don't hesitate to contact us.