K-Series Swap General Step-By-Step Guide
Jan 21st 2025
WORK IN PROGRESS, MORE INFO WILL BE ADDED LATER
Before continuing please read this blog post if you have not already:
K-Series Currently Supported K-Series Engines, Transmissions, Shifters, Wiring, etc
This will ensure you're not missing anything and have the correct K-series parts.
Engine Bay
This guide will assume you are starting with an empty engine bay. Leave the original shifter cables installed unless you are switching to aftermarket:
Remove the O.E. traction bar/front cross member too.
Hood Preparation
Part of the hood support structure needs to be removed for valve cover clearance. We have a separate blog post and video for this step here:
Brake Proportioning Valve / ALB
Relocate the brake proportioning valve ~4" further back. We sell a bracket for this purpose here:
K-Series Swap Brake Proportioning Valve Relocation Bracket
For ALB models: The factory location of the ALB components isn't compatible with this swap. If you want to keep ALB you will need to relocate all those parts (kind of a lot of work). Alternatively you can simply convert to standard brakes.
Subframe Trimming
Trim the rear subframe for clearance if your header requires it. Our blog post has information about what we currently know of header fitment: K-Series Currently Supported K-Series Engines, Transmissions, Shifters, Wiring, etc
Engine Wire Harness
Clean up the engine harness if it is a used unit. Remove the alternator/starter sub harness that connects below the starter.
Open it up and remove the large starter and alternator wires (they won't fit into the 3g fuse box and are too long).
After they are removed you should be left with 1 wire going to the starter trigger, 1 going to the knock sensor, and 4 wires going to the alternator plug. Cover up these wires again and reinstall the sub harness.
If you want new pre-made alternator and starter cables we sell a set here:
https://prelude-engineering.com/k-series-swap-alternator-and-starter-cables/
In order to have a working coolant temperature gauge you will need to install a single wire coolant temperature sender.
Depending on which K-series you have and which kind of water neck you will probably need a water coolant temp sensor adapter. You can find them made by Hybrid-Racing and K-Tuned:
If you purchased our K-Series Swap Adapter Harness then it will have come with a loose wire for the coolant temperature sensor. Open up the engine harness now and install the supplied wire from the temperature sender to the end of the engine harness. There will be extra length, secure it out of the way to the harness.
In order to insert the new pin into the C101 connector you will have to pry away the plastic block that secures the pins. Pry away the one on the same side as the connector clip:
After it has been pried away insert the pin into this location until you hear/feel a click. Then you can snap the plastic block back onto the connector:
To pass the harness into the cabin there is a specific spot on the firewall you can cut with a 1.25" hole saw:
If you bought our K-Series Swap Adapter Harness then it will have come with a new boot to install on the engine harness (for the firewall pass-through).
To get it onto the engine harness you will need to turn the connectors sideways and coat everything with a tiny amount of WD-40. You want the wire and inside of the boot to be slick.
Force the connectors through one at a time.
After you are done wipe the WD-40 off everything.
You should wait until the engine is installed and the harness is routed into the cabin before securing the boot onto the harness.
They way I do it is by starting an electrical tape wrap on the boot, move onto the harness two inches, then back onto the boot.
The final step is a zip tie around the boot to stop the tape from ever unraveling.
Rear Chassis Swap Bracket
The RSX Type-S rear mount needs one of the threaded holes drilled out so that you can install a bolt through the top. The O.E. RSX mount is made of plastic so you can't simply drill right through the insert in one go. It will overheat, melt the plastic, and the threaded insert will spin in the mount.
Using a 7/16" drill bit, drill out 1-2 threads at a time then dunk the mount in a bucket of cold water for 15 seconds. This will cool down the steel insert and stop any melting. Just keep repeating this process until you are all the way through:
Install the RSX Type-S rear mount onto the adapter bracket using the 30mm Allen tapered head bolts:
Install the adapter onto the rear subframe using 2 regular 14mm bolts and the Allen head bolt along with its special washer:
Right Swap Bracket
It's best to clear the area by pulling all the unused wiring into the fender and securing it with zip ties. The wires coming from the fuse box should also be adjusted so that they make a tight turn and don't interfere with the mount bracket once installed.
88-89 only: Install a M8x1.25 nutsert into this hole:
Set the mount bracket in place and start all the bolts (don't tighten). Once they are all in tighten the 14mm side bolts first then the top bolts.
One of the 12mm bolts will require the supplied fender washer and nut to be installed from underneath:
Install the RSX Type-S mount into the bracket:
NOTE: If you are going to run A/C with our K-Series Swap AC Lines the suggested/clean routing is under this bracket. You should probably install the line before this bracket in that case.
Left Swap Bracket Preparation
Install the RSX Type-S mount onto the left bracket using the large 17mm bolt and nut at the top. The 2 lower holes use the Allen tapered bolts and 14mm nuts.
You will install this mount bracket onto the chassis after the engine is in place in the bay.
Install K-Series Engine
You can install the engine from above or below, your choice. Just get it into the bay.
The transmission will need the O.E. aluminum bracket installed on it. Leave the bolts loose so that the bracket position can adjust.
Install the left mount bracket onto the chassis using a 14mm, 45mm long bolt in the rear and 1 or 2 of the black Allen head bolts in the front:
Install the post mount right bracket to connect the engine to the mount:
Check the 17mm nut and see if it bottoms out on the locating stud of the mount. If it does you will need to shave this stud down:
Install the rear bracket starting with the top 2 bolts. There are different holes to use depending on if you are mounting a K20 or K24:
For the lower holes you need to use the supplied "dogbone" spacer between the bracket and transmission. There are also 2 sets of holes here to use depending on K20 or K24.
You will probably need to jack/lift up on the rear of the transmission to align the holes and get the bolts started:
If you are going to run A/C you should make sure the A/C compressor is installed before you install the traction bar.
Install the traction bar onto the chassis. Push the bar up and finger tight the 17mm bottom bolts. Install the side 14mm bolts and fully tighten. Finally fully tighten the bottom 17mm bolts.
Install the front mount bolt into the correct hole. You will probably need to jack/push up on the front of the transmission to get the holes to line up:
Install the skid bar rear mount using the 2 supplied bolts:
Install the skid bar with 8 14mm bolts and nuts. Once again there are 2 sets of holes to choose from:
If you have the skid plate upgrade install it now:
The rear side brace has a few pieces and two sets of holes:
Shifter / Shifter Cables
If you are using your own sourced aftermarket cables and RSX type shifter then install them now. You will need to figure out the shifter mounting on your own but it will probably involve drilling new holes to bolt the shifter down in the interior.
We sell a cable bracket and shifter base setup that will allow you to use the stock 3g Prelude cables along with a 90-93 Accord shifter. This gives good clearance on the interior and you will be able to fit the stock center console for an O.E. look. Check it out here:
K-Series Swap Shift Setup A - Stock Cables
