Abdul's k24 or k20 Swap build/Guide with Complete Wiring diagrams

oil pressure sensor,vtec oil pressure sensors,Crank sensor

So lets prepare the engine 1st by replacing the sensors which are compatible with Civic Si wiring. 1st thing you should buy the engine.When it arrives inspect it for any broken sensors during shipment.So you may need to order those sensors too.
The sensors on backside of engine which need replacing/replacing the grips/re-pin the grip are Oil pressure sending unit,Vtec oil pressure switch,Crank sensor.
Before this all, i advice you buy Civic si wiring,so that installing new Grip/Sensor you will verify that the wiring plugs into it fine.

Oil pressure sending Unit
Located just above oil filter. If you have k20z2/k20A engine than you don’t have to change this unit. But if you are using k24a2,a3 or else you will you will see such unit which your civic si wiring plug won’t plug into.
the sensor being replaced is most common Honda oil pressure sensing unit.found almost on many if not most Honda/Acura cars.I found it from Junk yard.You can use your CRZ engine one also.


Difference




But for opening the sensor you will have to remove the exhaust manifold and its schild,because there is no space for the opening wrench to spin.


You will need 24mm wrench for it


If you engine came with an oil cooler,its oil pipe will hinder the new oil sensor location. A slight tapping with a hammer will be all that will be needed to clear the space.


After the sensor is installed.


When installing the new sensors/grip verify by plugging your Si wiring






While you are working at front side of engine its wise to replace the water body jacket which is pointing upward in pic below.This is k24a2/3

The problem of having this is the the radiator hose will have to bend at 180 degree and than come down to the radiator.which i found was hitting my radiator fan and one time radiator fan hit the radiator causung it to leak. Plus it will be difficult to find the hose which will ebdn 180 degree and come down. The easy solution is
http://k-tuned.3dcartstores.com/Swivel-Neck-Thermostat-Original_p_154.html

The beauty is that you can arrange this in any direction you want.which will be downward toward the radiator.But its 170$
So i have found an alternative from Aliexpress which work equally good.I am using this both in my CRZ(k24) aswell Honda Fit(k20)

Its only 34$ and quality is very good

Plus you can add your Coolant temperature guage sensor it it.


Final pic with it pointing downward


One slight suggstion if you intend to install your coolant guage sensor in this housing.The slight problem is that the guage port which is specific for this is not on right location.i mean if we install it in that port the sensor touched the thermostat valve inside of housing.

I went to machine shop and made them a hole in a screw for my water sensor.The screw used was the common transmission drain bolt on most Honda transmissions.


Finally its not hitting the thermostat valve


Final fittment

Crank Sensor

This one is slightly tricky to get wire correctly.So many confused posts over the internet.
The rule of thumb is " follow the sensor not the wiring grip or the ecu"
Below is the the crank sensor of a k24. and also of CRZ and Honda Jazz,Honda City.Its very common again.
I took it out for demonstration purpose only.No need to pull out the sensor.Just you need is re-pin its wiring grip.

Numbers written on it are 15130172-3925-RAA but its part number for k24a2 is 37500-RAA-A01.
Notice the difference between the wire location in grip ? The blue wire is signal wire,BRn/Yel is Ground and Yel/blk is its power.Above is k24 and down is k20.

Notice slight difference in the grips also from above

Now you will need to remove the white plastic plastic material inside the grip with a small screw driver or a dental pick etc etc and it will lokk like this.

Now its easy to pul the wire from back and re put them according to k24 wiring diagram.


This is after the re-pinning civic si wiring grip which now looks like the k24 wiring grip which came with my engine.(i bought k24 with its complete wiring so that i might need some wiring grips from it).


So to summerize all this,all three wire sensors sends its signal from a specific wire,light blue in our example(two wire sensors,only ground and power doest matter if you reverse the wires).So the ECu is looking for that signal from that wire.Its up to you to know which sensor is it and which is signal wire.So the wiring grips will follow the output of the k24 sensor not the k20.Although we are using k20 wiring and a k20 ECU.


Knock Sensor.

(Front side of engine behind the intake manifold)

If you have k20a/z3 than you don’t need change anything. If you have k24 than its got different knock sensor but both work the same and are interchangble. Only thing needs changing is the wiring grip. Easy way to do is cut the Crz wiring knock sensor grip and attach it to civic si wiring.
Left k24 knock sensor. Right k20A/z3


as you can see k20 knock sensor is slighly longer,so it will be near the engine and may be more sensitive.both will work.





You will need a 27 mm socket(a deep one) to open the knock sensor.area there is tight so the wrenches will not work.
Grips,Left is common Honda knock sensor CRZ/k24, right is k20a,k20z3,k20a2,dc5


Instead of cutting my crz wiring grip I found a grip from junkyard.
Common Honda grip Left, K20 Right


Tie and solder it to Si wiring,you can cut the grip of your CRz wiring.its same as k24

VTEC Oil pressure switch (Optional)

So far we have removed exhasut manifold to adress the oil pressure sending unit and intake manifold to address the knock sensor,water body jacket and starter wiring(i will tell next).
The JDM engines dont use the vtec oil pressure switch but Civic si uses and it has its wiring grip and ECU wont active VTEC if this sensor is not installed.( but if yoy are using Hondata flashpro you can disable it ).Its a very common sensor again found of honda Fit GD or Honda City 2003-08.and many more.(at end i will make list of all sensors which needed,ebay or junkyard).
On backside of engine,is Vtec solenoids

You will need to remove this bolt

and install the sensor in its location


Final fitment




So it all depends uopn the engine you got.may be it will have this sensor already.but most JDm engines dont have this like mine did't.So i had to install it but fiound out later i didt need it.
If you plan to use stock Civic si ECU than you need it otherwise skip this step.
I dont know whether Ktuner has option to disable it

In Short :The JDM ECU does't look for this sensor neither do JDM engines have this. US/EU engines has it and the ECu looks for it. But you can disable it with software and every thing & VTEC works just fine if you dont install it in a US/EU engine swap

Intake temperature sensor (IAT)

Here is you need to choose a path.Either you will use MAAF based ECu maps in Hopndata Flashpro or ktuner or you will use MAP based(speed density). If you want smoothness and drivebilty you should use hybrid map as does the factory honda ECU uses. If you plan on building the engine or boosting it in future than MAP based is good for you. I use MAp based map in bith my k-swapped cars and they are good.
For hybrid configuration you will have to buy Civic si MAAF sensor.It will have both MAAF and IAT sensor in it.No need to do any wiring for it. But if you want to use MAP bases maps,than you dont need that expensive MAAF (110$) sensor but a tiny IA sensor most common in older Hondas.



You just need to wire the IAT sensor two wires according to this diagram of Civic si

Just wire IAt wire to most right side wires of MAAF sensor grip of your Si wiring.i.e Grn/Blk and Red/Yel

Remember to buy the IAT sensor with its grip also. Honda Part No.: 37880-PLC-004.


And for those who want to use MAAF sensor,here is part number , 109$
Honda Part No.: 37980-RTA-003
Thanks Olliver for above diagram.

With this you have completed the major sensors replacement/Grip re-pin for a k24 engine or any k-series engine to accept Civic Si Wiring plug & play.
I hope this all doest seem difficults.Actually it is Fun.
Next i will cover most other hardware related details like axles,half shafts,break booster,CVT to manual conversion,headers,Ac compressor and O2 sensors and many more

Intake Manifold touching Alternator Bolt

While you are at front of engine,a very important point to note. As most of us know k-series engines came with verious intake manifolds,some have more low eng torque,some have higher top end HP etc etc.So if you choose to use same manifold which came with your engine than these next steps are not needed.
But if you are changing intakle manifold like i did, inspect carefully that after installing intake manifold the Alternator screw is not hitting with it or else you will short circuit wiring or short your alternator.
If thats the case just grind the screw end and it will solve the problem.But its easyly done when engine is out of car.

The rubber cover over the screw is protecting but with time the screw will tear it and touch the manifold and short circuit.Happened to me and i was saved by blown fuse insead of fire in car.


Blown fuse of alternator/generator.This fuse cannot be replaced.You will have to replace the whole unit. I got it soldered but that not good idea and risky.


To expose the screw remove the plastic cover from alternator by opening three bolts holding it using 8 mm key.


Screw exposed

Removal of covering bolt

Marked for grinding (black ink at end)

After grinding the tip



yaay it was easy but wait.Did you noticce the plastic cover is in such a way that now the alternator wire will touch other screw of left.We want it to face downward to be safer. So we also need to grind lower portion of plastic so that our alternator wire will exit down not on left side



After grinding plastic


Aaaand finally its now safe


I think i should also mention some basic tools you will need for preparing engine and wiring.

i recommend buying whole sets of keys instead buying one or two etc.
torque wrench is optional,if you want to do head work.grinder is also optional but will be handy.
You will note some keys are long,those are to open spark plugs as their sockets are deeep.i think 16mm is needed for spark plugs.
a grill machine also will be very handy. Alen key set and hex key set also if you want to modify VTC gear like i did (details later). i forgot the pic of hammer.and feller guage to do valve adjustments.
For wiring a crimping tool and some heat shrink tubes will be handy,plus paper cutter and a lighter.
So these are all basic and simple tools.

SheepGeeks said:

Thanks Abdul for posting this. I'm in the midst of k swap or bigger L15a turbo. I wanted to use RSX Type S because it's cheaper than Type R but most workshops here refuse to take this job.

I did thought of swapping it myself, it's such a fortunate to have you here posting the DIY step by step..

Click to expand...

Its very easy now if you have basic knowledge.The mounts,axles already plug and play.Just wiring is the part most people fear. So i have saved the wiring part to the end of this build because it is where i want to go in insane amount of details.with pics and videos.
Ok back to the build.
As k-series came with two type of oil pans, one are type R ones mosty on k20a,RSx,Civic si k20z3.Made from Aluminum.These have large oil capacity of 5L-5.5L But the have less ground clearance and so many times people shatter/crack them when hitting a bumps/obstacles etc
Other are Stailess steel oil pans mostly on k24's. They have slight less oil capacity(4.5-5L) but have more ground clearance and as they are of less rigid metal,they bend instead of crack/shatter.So they are very more durable and a lot of peice of mind they give. So if you have K24 swapping than no need to change anything.
But if you are swapping a k20,and want to use k24 steel oil pan,than you have to bend the oil pickup slightly so that it doest hit the oil pan.
Comparison,left k24 right k20


Cross section of a k20 oil pan with its oil pump.Notice how much less gap is there.imagine fitting a k24 pan over it will touch the oil pump pickup and will restrict oil flow and so oil pressure will be less


Note that for this to do you will have to flip the engine over,so if there is any oil in the oil pan it will spill out of engine and you will not like all the oil spilled on the floor.i learned the hard way( wife was not happy with black oil spilled on the floor )
So place the engine over two to three bricks,remove the oil drain nut and drain all the oil from engine.than it save to flip it over

By placing the oil pan over the engine.If the pickup is hitting it,the oil pan will not flushly sit on engine block


So its better to cut some metal from pickup.



After cutting its sits flushed.


And the final result with excellent ground clearance

I have done this to my k20 type R swap and it have zero issues and full oil pressure.

Break booster dilema

Break Booster
As Hasport is USA based company and there the CRZ/Honda Fit are Left hand drive(LHD) but in Japan and most Asia these are Righ Hand drive(RHD).So for guys swapping a k-engine in LHD this step is not needed as the break booster does't hit the block.
For RHD cars like mine JDm CRZ,the break booster hits the back side of engine.So solution is to change it to a shorter lenght.
Lucky for Honda Fit/JAzz guys, their break boosters are already smaller in lenght,so even in RHD Fit/JAzz there is not need to change the break booster.
HAsport knows about this problem and when I asked about it they told that they cannot further shift the engine to other side, so they advise to use 96-00 civic breakbooster. But what I have found that a better option is to use Honda Fit/Jazz breakbooster as its break lines are almost at same spot as crz. CRZ breakbooster master cylinder is 6.5” long where Fit one is just 4”.
Pic of beak booster and engine block

Honda Fit GE break booster 4 inches.You need to change the whole unit,only cylender cannot be changed.

The Fit/Jazz break booster is almost plug & play.Break lines need minimal bending if at all.

Final clearance of near 1.75" nehind the engine


and ofcourse at end break lines need bleeding and brake fluid changed.So keep some Honda brake or Any good DOT3/4 brake fluid with you if you have RHD CRZ.
The break fluid reservoir aslo shifted to right side and fixed with AC line.



The CRz OEM brake reservoir bottle wont fit.but no worry as the reservoir bottle came with the new brake booster is fine as it is more in lenght wise.so it fit near AC line. The CRZ reservoir is more in width wise which wont fit anywhere.


So if you have LHD CRZ,smile and move to next post.You have avoided a big troublesome step
for you RHD crz's you will have to order a Honda FIt GE break booster nad some brake fluid plus labor of shop will be increased.Suck for you guys but be happy that there is a solution atleast.
I have not found any brake performace decrease in my CRZ which now has Honda Fit break booster in it

Oil pump mode/Counter shaft removal(optional)

Another mode which can be done here. It is to remove the countershafts/balance shafts from oil pump. The k24 and Civic si and EuroR oil pumps have balance shafts in them to counter extra vibrations from a 4 cylender engine to make car more comfortable. But typeR and Type S oil pumps dont have those. So if you want extra revs and oil pressure its easy mode.Just cut the balance shafts.

I used a reciprocating saw to cut them,without removing them from oil pump.took just 10 mins.

Or you can remove and cut it some other ways



After removal


They are so heavy,i think more than 1 lb per shaft.So that removes rear 3 lb of rotational mass plus lot more oil pressure as pump is so easy to move now.Plus less chance of oil cavitation at high Rpms.

Remeber to block the oil feed hole to the balance shafts




Insert a shaft wood screw in it and pull out

You can use a 10 mm screw with some silicon to block it but some time its not threaded,so you will have to tap it for threads.


The end result


But as you can see in above pics a k24 oil pump is so big than a type S. So if you are using a k24 oil pump you cannot use a screw with head protuding out.it will hit the oil pump and oil pump will not fit. So in that case you will use a head less 10 mm screw.ot use a screw and shave off its head.
By this mode its safe to rev k24 upto 8000 rpms. I accidently reved engine upto 9600 rpms (i put rev limit to 7000 but rev recover to 9600 instead of 6900!, i know a very dump mistake,could have bent the valves or damaged the engine but it held)few times and nothing happened.So this mode is very nice regarding oil pressure and less cavitation.

Mount side bracket

Fediej said:

Nice write up, very detailed. Question on the oil pick-up though. Instead of bending it to clear the oil pan, couldn't one just cut it to the needed height, or are there other issues by going that route?

Click to expand...

Good idea.may be next time i will try it. I may be had this isea but dropped it in fear of opening the pickup point too much. i think Honda made it narrower for some reason.
Back to Build
If using k20a or k20z3 engine no need to change side mount bracket. If using k24 engine (other than of CR-V) than you will have to buy side bracket for right side HAsport engine mount.(When ever i will talk about righ or left side,i am reffereing to the view when driver is sitting on his seat inside the car)

You can campare the bracket which came with your engine to decide if you need it or not.

Here is HAsport user manual about bracket part


This is what came with my engine(k24a2/30) which was wrong part

This is place where it will mount.I know my engine looks dirty.I know.its a whole other story that the guy sold me engine which was clean on outside but was extremely dirty on inside.


Correct bracket

One thing HAsport mentions to order a bolt,but i ordered it and found that the mentioned bolt is thinner and longer. Instead i used one of the bolts from CRZ transmission.


Here i feel to share HAsport user manual which have very useful info regarding swap and what you will need mostly.I have not found it online anywhere.So i am sharing it.










THe last two pages contain very useful info




As i mentioned earlier that now they make the mounts for k24 transmissions also.So you dont have to buy k20z3 or Dc5 transmission seperately like i did.(1350$) and had to buy half shaft also for it (180$).
Instect your transmission also.Mostly the rubber boot cover is torn. Its very cheap.better to order new one before. i did't know this early so i rapired mine with sewing it and than applying silicon over it.





Honda Part No.: 22841-PPP-000

Hydraulic steering vs Electronic

As the CRZ and Honda Fit uses electronic power sterring(EPS) but the k-series engines came with either EPS or Hydraulic ones. As my k24 came with hydraulic power steering pump which i didt need.
Diffence between two.LEft is a k24 with hydraulic PS and right is k20 with idler pulley instead


So if i but the new pulley its like 162$ plus i will need a new belt too because the size diffence of two pulleys is huge


and if i do not change it what will happen ? as no oil will coming in and out of steering pump,it will soon jam up when engine is running. So i slightly modified it. Just removed the inner parts and left the shaft intact so that it moves freely without any oil.
Open this part by removing few bolts

After cover is removed,just remove other two circular parts simply pickying with hand,super easy


LAstly put the cover back and block both oil ports with silicon so that dust wont get in and get it jammed

This also is optional step.depends upon what type of steering pump/idler pulley comes with your engine.Also when buying engine prefer the one with idler pulley so you wont have to modify the pump or buy a new pulley

You will notice when using k20 oil pan over a k20 engine a gap is left between transmission and engine block.From here dust can enter the clutch and flywheel compartment.

So to cover it up Honda has a covering plate for it

Part Number: 21351-PNA-000
and is of Near 80$. So make sure your engine/tranny already has it.
Dont now why Honda clalls it 'torque converter case'
The gap is nicely covered by the plate


Please note that above step is totally optional.With HAsport mounts even k20 oil pans have good ground clearance.So you dont need to chnage it to k24 one. I did for my peice of mind because roads here have main holes the size of a crz(kidding) and spead brakers are build crazy high.

Axles and half shafts

As our engine is nearly complete lets talk about the axles for the swap. Both HAsport and Insane shafts make the axles for this swap. HAsport axles are rated near 300 hp and Insane ones are 500 Hp. But i was not sure Insane axles were compaticle with HAsport mounts. i though Hasport makes the mounts,so they have the data and measurments to where the engine resides in engine bay and what are the exact menasurments of axles. But i wanted 500 hp rated axles as in future i plan to supercharge this swap.
Si i asked Brain @ HAsport that can he make 450-500 hp axles?


In another email he told that now they have Mounts for k24 transmission too and he sharred some useful info too regarding k24 swap


Brain is really a nice person. He sharred his valuable info to his competitor for sake of us,although the Insane shafts guy was sure that Brain wont share such into to his competitors in making axles.


So there you have it.Now you can order Insaneshafts axles 500 hp rated plug& play for our swap.So mention which engine you will be using when contacting them as the half shafts of k24 are longer than k20.
For my Pakistani fellows want to do the swap. The axles can be locally made easy. The axles guy will use the outers of your CRZ axles and inners of K-series. So keep in mind when buying engine,dont just discard the axles which came with that engine.
Update 22-Aug-2020 : It has come into my information that oem axles and halfshaft of civic ex/sedan (Fd2),2007-11 with k20z2 engine(same as k20a3) are direct bolt-ons. so you can get them online easy and no custom modification needed. Its not as FD2 Type R,which i am not sure might fit or not.
Cr-Z width is 1740 mm where as civic is 1753. So it makes sense. Just 1.3 cm difference is no biggy.
As i have tested the Honda Fit/Jazz axles are an inch shorter than crz. And from data on internet.the base RSX(k20a3) has width of 1725mm.So Honda Fit guys can try those out.




And when buying engine do confirm that half shaft is there. My engine half shaft got stollen while transportation to my city. So i had to import one.costed me 180$
Part number is ???? but its Half shaft of Acura RSX type S manual transmission or Ep3. Always found used on ebay.124+103=227$ used.


Or you can buy Insane shafts in 250$



Remebr to order for manual transmission as auto ones are different.way differnt.THe auto one has silver metal body in which there is three screw pattern shown above. the manual ones have cast iron. The three bolt pattern is different in manual vs auto.
Halfshaft also called intermediate shaft.
Note: k24 half shaft is longer than k24 so axles of that side will be different for k24 or k20. This happneded to me as i am using a k20 half shaft in my Fit. I ordered axles from Insaneshafts and one axle was wrong. Luckyly i am using k24 Halfshaft in my crz. So i will swap that halfshaft to Fit and my Fit k20 one to that and it will work. These are located uder manu, 'axles' 'honda' than scroll to 'Insight'. You can order individual or both. Part numbers are
IS-038 and IS-018



These will work for An Insight, Fit, CRZ k-Swap using Hasport mounts.
Update: The Insaneshaft axles did not fit in my Fit. One axle is shorter and one is longer. So disappointed.
If your gear has LSD in it than you need to order Honda manual transmission fluid Advanced Protection not the simple Honda MTF.

Hondata Intake maifold gasket

Again an optional but worth it and cheap.The k-series intake manifold gasket is of metal.So all the heat from head transmits to intake which reduces performance. Hondata and other companies have made Phenolic gaskets which reduce intake temps very much,and its only 50$




Remeber the current cant flow from plastic.So you will have to pass a ground wire from any bolt from your intake manifold to chassis.Also recommended by Hondata

I know you guys want to see the actual swap happening.Dont worry it will come.i have all the pics and videos saved. Near 500 pics.some time very diffiult to search from them what to choose. Swap already has happned three months back. But i want to document every detail so that one is totally prepared bofore going to a workshop.
Just a teaser picture when engine was ready...


A tip, engines are quite heavy.look what it did to the tiles on floor wife was not happy again So if you want to do it in home,choose some place which is strong enough.

Block a port

TheRickster said:

You're truly doing the lords work.

Click to expand...

Thanks a lot but i am afraid putting too much details will put fear in people that is is difficult work.infact it isn't. Its quite fun to do actually.
Back to build.
Another optional step.
Honda desinged a port from cylender four to coolant hose which goes inside to heat up car heater. purpose is to get car heater making heat early in very cold temperature. So if you live in sub zero temerature countries,dont block it. But if you live in warmer regions than blocking this port will run coolant a tad cooler and less work for radiator and fans to remove heat from coolant system.

On side of engine you will see heater hoses going into this structure


Remove it by removing four screws.


If you place a screw driver in poer you will see it leading to a hole in exhaust side of cylender 4




Other side of this port is totally blind(empty,leading nowhere)



Block the port with your favourite material. i used scotch brite wool guaze