Honda Swap Guide – How to Plan your Engine Swap

Honda Swap Guide – How to Plan your Engine Swap


Putting together the best Honda engine swap can be increasingly difficult, just because of the large number of options before you. Using this Honda swap guide, you’ll be able to find the best combination of parts, axles, engine mounts and wiring to build the best Honda engine swap. Of course when you are looking for Honda engine swap tech tips, our collection of tech tips at My Pro Street can help.

Whether you’ve sourced your Honda engine swap from a junkyard or a JDM importer, there’s a lot to plan for. Before you can plan any Honda engine swap however, you need to remove your old Honda engine. Today we’ll be going over a comprehensive plan of attack for your Honda. Our Honda swap guide can help you make the right choices from start to finish, so let’s begin.

Picking the right engine swap

the important thing here is that you don’t choose an engine that will provide much upgrade. After all the engine transplant might be a lot of work, so you definitely want to make sure you’re upgrading your Honda. When it comes to picking the right engine it’s best to choose one the best amount of potential.

honda swap guide 1This doesn’t mean you should downgrade your engine however. If you’ve got a Honda Acoord with a J series V6 in it, there’s not much sense in downgrading to a H22 in other words, despite the aftermarket modification support.

Likewise if you own a car like a Type R or a Civic SI, it doesn’t make much sense to strip out the engine and swap in another. unless you’ve blown up the engine or unfortunately had your car stolen much of what makes your vehicle so special is what’s under the hood. For this simple reason it’s always a good idea start with the lower trim model like the Civic DX.

Special Considerations

There’s always a handful of special considerations that you think about before considering swapping in another engine. Some of these considerations, like smog or emissions tests in your state are gamebreakers. if you happen to live in a state with strict emissions standards, to the right amount of homework so that you don’t get into legal trouble.

honda swap guide 8Likewise you should always consider the pros and cons of your prospective engine swap. Just because an engine swap is unique or is possible doesn’t mean you should jump on board.

One of the biggest problems when it comes to engine swaps is of course the wiring aspect of it.

If you’re considering a Honda swap and don’t want to do the wiring yourself, look into the wide range of plug-and-play harnesses that can help you.

Some of the other special considerations might range from what transmission would fit, shifter considerations as well as axle combinations and more.

Plan your Budget

If you’re still planning on completing the Honda engine swap, the two biggest things to pick out are the engine and the car. If you already own the car, you’ll want to pick the right engine for it. Make sure to write down and complete a budget before embarking on your Honda engine swap journey. Always leave a little bit of fudge room in case of emergency or maybe getting a part that was incorrect.

When importing a JDM engine there’s always a chance that your distributor or sensors may come broken. Many of these engine sets are left out, exposed to the elements for long periods of time.

k20-swap-guide 1Most important thing to remember however is to remain realistic. There are many people who get grandiose dreams and set high expectations for the Honda engine swap.

While it’s certainly admirable to try something new and be different, you don’t want to go overboard. In the quest to be different you don’t want to set your expectations so high that you’ll never complete the engine swap itself.

Once you’ve picked out the engine in question, the next part is to figure out what ECU you’ll be running. This is another area where the wonderful world of Honda interchangeability can make things more difficult than they need to be. need a guide on Honda ECUs? Check out our primer here to figure out which engine computer you need to properly complete your Honda engine swap or to wire in VTEC.

Which Harness?

So you decided to do the wiring in your Honda swap yourself. While it’s not overly difficult it will require a lot of attention to detail. For the simple reason it’s a good idea to plan out your course of action before hand. Although it’s usually a good idea to use the donor harness from your engine swap, you may be surprised to know that you always need to.

honda engine swap guide 3Aside from various electrical connectors most of the donor harnesses won’t be a much better candidate than the harness in your car already.

If you’re donor vehicle did not come with VTEC already adding it is simple and requires just a few wires. when it comes to Honda harnesses most of them terminate under your dashboard to complete the electrical system.

In some vehicles or Hondas this collection occurs on the firewall, or at several sub harnesses along the shock tower or glovebox. If the vehicle your swapping into is available in a higher trim that happens to have the engineer swapping in, forget about a donor harness. For example, if you are swapping in a B16 to a 1996 Honda DX, save some money simply add the wiring you need.

By retaining the original harness that came with your car you’ll save money and time. You won’t need to connect the underneath dashboard harness. Further, if you purchase a JDM engine the harness will lead the wrong way because those vehicles are right hand drive.

There’s a few different factors to consider when thinking about the right engine harness the got the junkyard motor. Firstly the engine harness must be a USDM one, meaning it’s headed the right way for a left-hand drive vehicle. Secondly you want to inspect all the connectors to make sure that none are chopped up or damaged. Thirdly it’s also important to make sure that you’re picking the right OBD generation that matches your engine. And lastly remember that you’ll only be able to interchange engine harnesses between vehicles that are the same.

Honda Swap Guide Wiring

Very rarely does any Honda swap bolt right in without some small amount of electrical modification. Whenever you’re replacing an entire engine with a different one, there’s going to be some small changes. Adding eliminating or modifying electrical connectors should be small enough task that you’re comfortable with if you are planning a Honda swap.

honda swap guide 5Of course one of the main reasons to wire up your engine swap will be to add VTEC. Luckily this is just a few wires as previously mentioned.

Depending on your car and motor you may need to add a few sensors as well. Before bolting in your engine make sure to locate the sensors and where they go.

These extra sensors can often be installed by using a part of unused harness or hacking apart a junkyard one.

Electrical tools you’ll need to complete this job include but are not limited to; a soldering iron, a digital multimeter and electrical tape.

Part 2 of our guide will walk you through the engine mount possibilities and what combination of Honda parts fit what.