This FAQ page has been updated and expanded in September 2020 to include information about all of our K swap packages for any chassis.
Which K series engines are best for this swap?
For most customers, a 2.4L Acura TSX engine is the ideal starting point. The K24A2 from the 2004-2008 TSX is the most potent K24 in stock form, and can also be built to make significantly more N/A power.
For Miata customers specifically, the K24Z3 from the 2009-2014 TSX is also a fantastic choice. Our K24Z3 swap is lower cost, and retains the factory Miata subframe thanks to the single exit exhaust port.
For a comparison of both Miata packages, see our blog post here. We currently only support the K24Z3 platform for the Miata chassis, and recommend a K24A2 for other cars.
Can I use a K20 engine, or a K20 head?
As of 2021, the only K20 engine block that is compatible with any of our mounts is a K20Z3 (2006-2011 Civic Si). We no longer support the K20A2 and K20Z1 blocks due to the lack of usable bolt hole locations on the intake side of the engines. Since the K24A2 and K24A engines are less expensive than a K20 and make more power, that is always our recommended starting point if you're installing a traditional four exhaust port engine.
A K20 (PRB) cylinder head is compatible with all of our swaps, as long as a PRB style intake manifold and PRB upper coolant neck to be used.
Can I use the K20C1 from the Civic Type R?
No, the new turbo Type R engine shares no similarities with the older K series engines and is not compatible with our products.
Can I use an F series from the S2000?
No, none of our K series parts are compatible with an F series engine.
Can I use a JDM K24A engine or the K24A3 available in Europe and Australia?
Yes, both of these engines are nearly identical to the K24A2 available in the U.S. Customers purchasing a JDM engine should make sure they are receiving the K24A engine with an RBB cylinder head and a 200 hp rating. Depending on accessory belt configuration, JDM engine users may need to install a USDM water pump housing and alternator to be compatible with some of our products.
Where are the best places to find engines?
We recommend checking online salvage yard databases like www.car-part.com. JDM engines can be sourced from JDM engine importers around the country as well.
How much power will I make with my K24 swap?
This depends on a variety of factors, as well as dyno tuning. Generally speaking, we see 220-230whp from stock K24A2 engines with our bolt ons, and 200-210whp from stock K24Z3 engines.
Stock K24A engines are often upgraded with cams, head porting, and high compression pistons to make 300whp N/A. Forced induction can generally make 500whp safely on a stock K24 engine.
Will you eventually make swap parts for the NC/ND Miata chassis?
Yes, we may eventually build swap parts for both the NC and ND, however, there is no timeline on availability for these products.
Do you make swap parts for an FC, FD, E36, RX8, Lotus, Datsun, etc?
If the chassis is not listed on our website, we do NOT currently have product offerings for it. All available products are listed on the website. As we add more vehicles to our supported line-up, they will be added to the website. Subscribe to our email newsletter at the bottom of this page for insider updates.
What transmission do I use with my RWD K swap?
Since K series transmissions are all FWD, our swap packages include an adapter plate and flywheel designed to work with the factory transmission that comes in the donor vehicle. NA and NB Miata transmissions work with Miata swaps, E30 swaps work with the E30 Getrag 260 transmission, and so on.
If we offer a transmission upgrade for a certain chassis, it will be listed separately on our site, such as the E36/E46 transmission options for the Miata.
Clutch options are specific to the flywheel supplied with our swap and is detailed on each product page and in each installation guide.
What kind of engine management software will I need?
Our current swaps are designed to work with Hondata Kpro4, installed in a 2002-2004 Acura RSX ECU (base or Type S, manual or auto). Our larger swap packages include a wiring conversion harness for this specific ECU. Our KPower 86 swap uses a Haltech Elite 1500 ECU.
Many customers have used standalones with their conversions, including Haltech, Megaquirt, and ECU Master. We do not offer wiring solutions or technical support for customers using ECUs other than Kpro and Haltech.
What engine wiring harness do I need?
We only support wiring your vehicle with a 2002-2004 Acura RSX engine wiring harness and charge sub harness (manual or auto). This can be sourced used, new from Acura, or our custom RWD KPower engine harness can also be used. Regardless of harness choice, it must be pinned for a 2002-2004 RSX. The stock K24 engine harnesses are NOT compatible with these swaps for a variety of reasons. KPower 86 customers must use the specific engine harness we carry for the swap.
Does the steering geometry change with any of your swaps?
No, we make a point to retain the factory steering rack placement in every swap we offer in order to retain factory steering feel.
Will my factory gauges work with my K swap?
Yes, all gauges work like stock with all of our engine conversions.
Can I retain A/C and power steering with my K swap?
We offer bolt-in A/C and power steering options for the NA/NB Miata chassis as well as the 86. These options will be added for the E30 shortly, as well as all other K swaps we release in the future.
Is a radiator upgrade needed?
Stock radiators work fine for street cars, but if the car is going to see heavy track use, we recommend upgrading to an aluminum radiator. N/A K series engines don’t generally have any overheating issues.
How difficult is the wiring for a K swap?
That depends on the chassis. The E30 and 86 wiring is plug and play, while the NA and NB Miata requires the dash to be removed so some splices can be made. See our installation guides for detailed wiring instructions.
What exhaust will make the most power?
In every application, we have always found the K series to make the most power with a 3” exhaust. Every header or downpipe we offer is terminated with a 3” exhaust flange, and our Miata race exhaust only comes in 3” diameter.
How much does a K swap weigh compared to my stock engine?
Since the K series is an aluminum four cylinder, we see about a 30 lb drop in weight with a K24 Miata swap, and roughly a 150 lb drop in an E30 originally equipped with the M20. The 86 chassis drops about 140 lb when the FA20 is replaced with a K24 and all accessories. We will publish weights on new projects as they are completed.
How are oil pan and hood clearances?
Our oil pans all sit flush with the bottom of the factory subframes (or a bit above it in the E30 and 86). The only chassis that requires additional work for hood clearance is the NA Miata. We offer a modified K24 valve cover and also a set of subframe spacers to get the engine below the factory hood skin.
Do your swaps fit right hand drive (RHD) vehicles?
Most of our components are compatible with RHD cars, including all oil pans, adapter plates, and flywheels. The only engine mount that is not compatible with RHD is the right mount in our K24A2 Miata swap.
Additionally, none of our exhaust headers or downpipes are compatible with RHD steering columns.
If you are looking to install a RHD K24A2 Miata swap, we are able to supply you with an unfinished subframe with no right mount, but with RHD steering rack mounts already welded on. We have had a number of RHD customers complete this swap by finishing the fabrication on their own. If you’re interested in purchasing a swap package like this, email us at firstname.lastname@example.org.