The K series swap is quickly overtaking the DOHC B series as king of all Honda engine transplants. Modifying Hondas is still a very popular choice, although it’s certainly less common than it used to be. Apologies to all the SOHC ninjas out there, but if you own a Honda Civic, your choices are rather limited with the stock 1.6 liter Honda VTEC engine.
Displacement is limited and your ultimate horsepower goals in naturally aspirated form aren’t going to put you into any winner’s circles. Swapping in a DOHC VTEC B series is easy to do and simple when you have the right plan of attack. If you plan out your Honda engine swap, there’s no reason why you can’t complete it in a weekend.
This is what our K Series Swap Guide is for, to help you plan out your i-VTEC DOHC engine swap int your favorite Honda. If you want K Series swap part numbers, accessories and more check out the K swap tutorial here.
Why a K Series Swap?
This guide is for people who want the power and torque available in a K24 or K20 engine swap in naturally aspirated form. Although turbo Hondas are great, they have their share of problems as well.
Swapping in a B series is still easy to do, but the supply of DOHC VTEC engines is shrinking. Honda hasn’t built one since 2001 and the price tag for these B series swap engines are getting to the point where choosing a K series is preferable. Many of the B series engine candidates also have issues, like stripped bolts or damage that need repair because of their age.
Enter the K series iVTEC engine swap, an excellent choice for the new modern Honda engine swap. If you are considering a Honda engine swap, here are just some of the reasons why a K series engine swap is better than a B.
Availability of a K series swap
The new iVTEC K series engine swap is plentiful and like most Honda components are found in many different vehicles. The K series swap is available in the new Accord, Element, CR-V, TSX and RSX. These engines and transmissions have several different variations but the lowest horsepower number you can find is 160. The torque powerband is much wider than any B series and gives you an excellent base for more modifications.
Best chassis for K series swap
Although the 2001+ Honda Civic is easier for any K series engine swap, there are several reasons why you should pick an earlier model. The 1992-1995 Honda Civic is still one of the lightest and the 1996-2000 Civic still uses a double wishbone front suspension. This means the earlier Honda Civic’s can handle far better than the 2001+ versions. Both Civics are excellent choices for any K20 engine swap.
Both Civics share the similar engine mount layouts and the hatchbacks typically check in under 2300 lbs. This gives you an excellent power to weight ratio right from the get go.
When you are selecting the chassis it’s also a good idea to give some thought to the K series swap mounts. The best mounts on the market are either the HASPORT engine mounts or the K series mounts from AVID Racing. These mounts are modified to fit into your Civic EK or EG and give you the best possible fitment for your engine swap. Although you can swap a K series into a automatic Civic, it’s best to pick a chassis with a manual transmission layout.
For the 1996-2000 Honda Civic the weapon of choice would be the CX hatchback. For 1992-1995 Honda Civics the best chassis would be the Honda VX. If you care about emissions or smog however, it’s best to go with the 1996-2000 Honda Civic so you don’t need a new fuel tank to pass smog.
How to Pick the right K Series Swap
There’s so many vehicles to pick your K20 or K24 donor engine from. No matter what engine you are picking, it’s a good idea to have an end goal in mind so you don’t make a mistake or pick parts that don’t work well together.
K20 or K24 engines can be found in any of the new Honda vehicles. Further you can combine the 2.4 liter K24 bottom end with a K20A2 head from a Acura RSX Type S. You can stick with the K24 although there’s a few different reasons why you want to avoid them. One of which is the EGR which is an integral part of the 2.4 liter K series and can prevent you from smogging your Honda swap.
If you want to stick with a good 2.4 liter K series candidate, the Honda CR-V is an excellent choice. This K24 doesn’t have an EGR in it, and it’s possible to find a manual six speed K series transmission to fit the CR-V engine from a Honda Element.
Later K24 engines like the one found in the Acura TSX can be overly difficult to swap. Further the TSX engine uses the Drive By Wire system, which needlessly complicates your K series engine swap. Because the transmission and engine have different ECU’s and harness differences, you could potentially be walking into a Honda swap problem. Outside of a handful of exceptions however most of the K series engine harnesses are the same.
When you are looking for the ultimate drop in K series engine, it has to be the one from the Acura RSX Type-S. This version of the K20 is known as the K20A2 and it’s i-VTEC design can offer you the best platform to build your Honda swap on. The RSX K series engine boasts the highest compression you will find on US shores.
Of all the K series swap candidate engines the base RSX is probably the one you want to avoid. If you are having problems locating a Type S engine, try taking a look at the 2.4 liter options in the Accords, CRV’s and Elements. Although these will have less horsepower out of the box, you will have a ton of torque to choose from and it can take a Type S or TSX head later.
If cost is not a consideration of course, the JDM K20A is the way to go. You’ll have 24 more horsepower than the Type-S and it comes with a LSD to boot.
How to Pick the right K Series Transmission
If you are picking engine and transmission choices from a wrecker you aren’t going to have much choice, unless you intend on taking them apart. Some of the obvious choices would be a six speed transmission from the RSX Type-S or the Acura TSX. If top speed gearing is a concern, you are best off with the Type S as the TSX transmission is geared for low RPM operation.
The new Civic SI also has a manual gearbox and is almost an exact copy of the RSX save a few changes. The Civic SI has a lower first gear ratio but the final drive is much higher. The Honda Accord also has a lower final drive transmission, making it an excellent choice for turbo K series engine swaps.
You can swap any of the final drives or gears from a five speed K series transmission as long as the target is also a five speed. The same goes for six speed transmissions but you cannot go from six to five or five to six speed gearboxes.
K Series Swap Checklist
- Engine mounts
- Custom Axles
- Wiring harness
- Rear facing K series header
- Fuel pressure regulator
- 2002+ Civic Si throttle cable
- 1990-1997 Accord shifter box or RSX shifter box
- 1994-2001 GS-R radiator hoses
- 2002-and-up Civic Si idler pulley – Installs in power steering location
See our comprehensive K series engine swap part number guide and get your K20 project started!
Have any questions about our K series engine swap guide? Leave us a comment below and let us know!!
I was wondering would it fit a K24A Accord OBD2 Engine JDM Engine K24A on my 1994 Honda Civic ? Any suggestions ?
Hi Yancario, thanks for reading!
yes! that K24 would look great in your EG! For more information on the swap, check out these guides here :
http://my.prostreetonline.com/2014/09/25/k20-swap-guide-what-you-need-to-swap-a-k20/
http://my.prostreetonline.com/2016/04/21/k20-ep3-swap-guide-need/
http://my.prostreetonline.com/2015/02/20/k-series-transmission-differences/
Thanks for commenting and reading! let us know how your swap turns out
K24 motor swap into 96 del sol
My 1.6 single overhead cam ( block cracked)
Will it bolt into trans or will I need 2.4 trans ??
Hi Kris,
unfortunately if you are wanting to adapt a D series transmission onto your K24 swap that won’t work. You will need a K series transmission at the very least.
Thanks for reading.