Top Ten Honda Engine Swap Tips

Do yourself a favor when remove the throttle position sensor (TPS) when you are removing your engine or installing your donor engine. Many times when raising or lowering your engine into or out of your chassis, this sensor can break or become damaged.

This can be especially true for JDM engines that have been shipped halfway around the world, usually by people who could care less what happens to some sensor.

Remove TPS or Throttle Body -

Skip the drama and simply remove your TPS ahead of time. You will need to recalibrate the TPS upon reinstallation, so if you don't have a multimeter handy, remove your throttle body instead. If you are swapping a B series engine into your Honda, take a look at our B series TPS service guide. This guide contains the B series TPS wiring diagram you need to service and calibrate your throttle body.

This sensor can become another cost and repair that you Honda engine swap project didn't need. Don't let this happen to you and remove this sensor before it can become damaged. Of course you can always save time by simply picking up a BlackWorks TPS sensor, or a replacement BLOX TPS sensor to save time in your B series swap.

If you have a donor engine from a JDM importer that's not the same year range as your donor chassis, some work will be required before you can complete your Honda swap.

Convert your distributor - Lots of people just go out and buy the right distributor for their engine harness, which tacks on another 150 dollars in cost and parts. Instead convert your Honda OBD to match the engine harness by repinning or modifying your ignition distributor terminal.

One of the biggest mistakes for many Honda swappers, the air conditioning compressor is disconnected before you remove and install your new Honda swap. You then have to fill the AC compressor because you've released all the freon inside of the unit.

Save Money - Instead of doing this, simply unbolt your AC compressor from the driver side lower engine mount. Do not disconnect the high pressure or low pressure side of the compressor, simply unbolt from your engine and secure it to your chassis safely using bungie cords.

When you install your new engine swap, you can reconnect the Honda AC compressor to your new motor, without having to fill or pay someone to fill your compressor again.

Easier said than done in many cases, because there's so many variations of the same engine and displacement, it can be easy to mix up what is what.

Identify - Make sure you know what engine and transmission you have. If your transmission identification sticker has fallen off, take the proper steps to identify your parts. Failure to do this could lead to a mismatch in clutch parts, or your slave cylinder which will only add time and more cost to your Honda engine swap.

You can also take the time to identify your Honda ECU and any other components that you aren't sure of to complete your swap the first time.

When you are getting ready to put your Honda engine swap into your donor chassis, exhaust fitment problems can stop you cold in your tracks. When you are purchasing or importing a JDM engine, your exhaust parts should match before you start removing your factory engine.

What to check -

The B pipe gasket - Remember just because you have a JDM B series header, it won't always match up to your B pipe, or the second half of the header that runs under your oil pan.

The catalytic converter flange - The size of collector from the end of your exhaust header, where your catalytic converter connects to the header. Many times a JDM header will feature a 2.5 inch doughnut style gasket. Make sure that you have the right size gasket and catalytic converter flange that matches.

Honda engine swaps are popular because of the incredible flexibility and ease in which parts from one car fit another. You can find replacement parts, engine mounts or exhaust parts that all interchange with your new donor motor, or chassis. If you are upgrading your clutch, consider upgrading your clutch master cylinder as well, it will increase your clutch engagement and decrease shift times.

Input Shaft Spline Fitment -

This feature is a blessing as well as a curse however. If you are building your own Honda Swap by putting together a transmission and engine separately, it's a good idea to double check your clutch disc.

Lots of would be Honda engine swappers get to the final stages of their swap, and wonder why the transmission refuses to slide onto the engine. This can happen when you have the wrong clutch disc, or the incorrect spline count, which happens more than you might think.

Take a few seconds and slide your clutch disc over the splines of your transmission shaft. This ensures that your parts fit, and you won't be left with a motor and transmission that won't go together.

Depending on the scope of your Honda engine swap, you may or may not need this entry of the top ten Honda engine swap tips. The VTEC variable valve system from Honda is one of the primary factors that engine swappers look for in a donor engine.

Check your VTEC components - When you are swapping your Honda, do the proper planning to make sure your VTEC will work correctly. If you own a non VTEC Honda and have to wire VTEC for your Honda swap, make sure to check both your VTEC solenoid as well as your pressure switch.

Failure to take the proper steps could leave your Honda engine swap without VTEC, or VTEC not working.

Slimline fans are a must for any Honda engine swap, because you don't want your new engine swap to overheat. This step is often overlooked by the would be Honda engine swapper, because they aren't sure how to wire the slimline fan into the Honda wiring harness.

Wire in a fan relay - Never wire a slimline fan directly into your Honda wiring harness. There's differences between the draw and voltage between your factory fan and your new unit. These differences could lead to the fan prematurely dying in a best case scenario, or cause your car to catch on fire in the worst case scenario.

Don't let this happen to you, properly install a slimline fan to your radiator by using a radiator fan relay.

When it comes to planning your Honda swap, this tip is probably one of the most intensive. Locate and find what ECU you have, and what ECU you will need to operate your Honda engine swap. This tip on the top ten Honda engine swap tips list is very similar to the OBD tip, in that you need the right ECU for your car and engine.

EEPROM - For just a few dollars and a soldering iron, you can modify your Honda VTEC ECU to accept a ZIF EEPROM socket and memory chip.

This is perfect if you want to add a turbocharger kit to the Honda swap at a later date, or add a piggyback computer to your Honda.

It's a minor detail but one that can have a profound effect on your Honda engine swap, and the reliability of your swap. Using non fuel injection type hoses like the one shown will lead to premature coolant or fuel hose failure.

Fuel injection style hose clamps - Stay away from "worm" style clamps and use fuel injection style fasteners that will not damage your hoses.

This tip is easy to take care of before you put your engine in. Identify what kind of clutch slave cylinder your transmission calls for, whether it's a cable style or hydraulic.

Slave Cylinder - Find out what you have and install the proper kit or appropriate hydro-to-cable conversion or vice versa. The last thing you want to get hung up on is your clutch slave cylinder in your Honda engine swap.
*Master Cylinder - * Upgrade to a S2000 unit for hydraulic clutch transmissions, or opt for an aftermarket one for competition use. It will increase the hydraulic pressure and shorten your clutch throw, making it easier to shift and slip your clutch.