Wanting to swap a DE into a E car?, read here to find out how. Options

[fos240]

EDITED: August 30th to make it easier to understand some of the text.

the topic of swapping a DOHC KA into a SOHC car has come up a few times. here is what you'll need to do each of the swaps. i hope this gets pinned, but no biggie if it doesn't. also, if i leave stuff out please feel free to add to it.

before we get to each of the engines, here is the car prep that needs to be done.

-the accelerator cable needs to be changed. the sohc cable is shorter and doesn't have enough travel. i have heard that people have stretched it across the engine and when i tried that it held the throttle plate open. maybe it can be done, but it will look like crap.

-the power steering lines need to be changed over. the s13 lines work better, but with a little bit of finesse (adjusting) i was able to make s14 p/s lines work in the s13 coupe. the s13 dohc p/s resevoir will bolt right on the strut tower. the s14 resevoir doesn't fit quite as well, but can be made to work. if using a s14 engine, the ps pumps have different connections for the ps lines. I.E. if you get a s14 engine and want to use that ps pump, you will need the s14 lines. if you are using a s13 engine and are using that pump you will have to get s13 ps lines. the lines won't interchange with the pumps, but the pumps will interchange on the engines. (this will be posted again further down).

-the tachometer will need to be changed out to a dohc s13 unit. the signal is different between the two. the tach can be removed from the cluster, or the whole cluster can be changed. (the s14 tach won't work, because the physical size of the tach is different.)

-the water temperature sensor from the SOHC engine needs to be used. for some reason the resistance is different. if you use the stock sensor from the DOHC engine, it will register on the gauge as being higher than with the SOHC unit.

-go ahead and remove the coil assembly from the car. the SOHC one won't work on the DOHC engine. i'll explain more on this down further

S13 DOHC engine

to swap a S13 DOHC, all the above needs to be done.
-use the coil setup from the DOHC donor car.

-the engine wiring harness and ecu will need to be replaced with one for the s13 DE engine. the dash connector will need to be cut off the SOHC engine harness (where it meets the dash harness), and soldered to the DOHC engine harness in the same location. there will be wires that are left floating so don't worry. all the wires that need to be connected will be color matched. for example: just put red to red, and white to white, ect.

-if using a stock exhaust system the down pipe from sohc will bolt to the s13 exhaust manifold there won't be any issues. the egr will work as well.

-the mafs from the dohc car will need to be used. the sohc mafs won't work with the dohc ecu. if you want to change the plug you can even use a s14 mafs. it has a bigger opening. NOTE*** i haven't done this. i am basing this on the fact the SAFC II shows both mafs to be the same type. (type 5 in the SAFC library)

-the heater core hose locations are the same and will work between each.

-the s13 ps pump has to have s13 ps lines. s14 ps lines won't bolt up without modification.


95 s14 DOHC engine

-the 95 engines have the same electrical connectors on the intake as the s13 dohc engines. you can use a s13 dohc wiring harness and ecu with no problems.

-if you use the s13 engine harness you'll need to change the distributor to a s13 dohc unit and add the coil assembly. (all s14 distributors have internal coil).

-if you use the 95 s14 harness there are a lot more wires to weed through. you will also need to make sure you update to a s14 tranny if you want to keep the ecu happy. because the crank angle sensor is located on the tranny bell housing. the s13 tranny doesn't have a provision for the crank angle sensor. if you don't care about the check engine light, then use a s13 tranny and don't worry about the crank angle sensor.

-if wanting to use a 96+ harness and ecu, then all the sensors have to be changed including the tps. best thing is to not use a 96+ harness and ecu.

-regardless of which harness/ecu combo the mafs will need to be updated to a dohc unit. easiest thing is to use the mafs that fits the plug (minus the sohc unit).

-the egr tube will need to be changed because the angle and placement to where it connects with the exhaust manifold is in a different location between s13 and s14. i don't know if a s14 after market header will have clearance issues on a s13. best thing to do is to change the exhaust manifold/header over to a s13 unit and change the egr tube or eliminate it altogether. (i don't condone this, i'm merely pointing out the possibilities.)

-the heater core hoses are different sizes between the s14 engine and s13 chasis. you will have to rig something up to work. the location of the outlets on the engine is different as well. on the s13 engine/intake plenum they come out the back of the engine. on the s14 engine/intake plenum they come out the side underneath the plenum.

-the s14 ps pump has to have s14 ps lines. s13 ps lines won't bolt up without modification.


96+ s14 DOHC engine

-the easiest thing to do here is replace the intake manifold with a s13 manifold and electronics. and just follow directions above.

-and again the 96+ engine harness and ecu can be used, but the wiring is more involved. with the exception of the engine harness and electrical connectors, everything else swaps just like above.

-the s14 ps pump has to have s14 ps lines. s13 ps lines won't bolt up without modifcation.


frankie

[Jsquared]

traffic dude, i got PWNT by traffic (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/006_grin.gif)

but thanks for the info, very good stuff for those on a budget trying to get a nicer KA into their car...

[fos240]

ok all done. i may have forgotten an item or two. either add to it or let me know and i'll add to it.

frankie

[planb]

-the water temperature sensor from the SOHC engine needs to be used. for some reason the resistance is different. if you use the stock sensor from the DOHC engine, it will register on the gauge as being higher than with the SOHC unit.

So, im assuming if you use a whole dohc cluster, the dohc water temp sensor will work fine...

and

are you 100% sure you cant use the sohc coil/ignitor assembly on the (s13) dohc?

[fos240]

-the water temperature sensor from the SOHC engine needs to be used.  for some reason the resistance is different.  if you use the stock sensor from the DOHC engine, it will register on the gauge as being higher than with the SOHC unit.

So, im assuming if you use a whole dohc cluster, the dohc water temp sensor will work fine...

and

are you 100% sure you cant use the sohc coil/ignitor assembly on the (s13) dohc?

on the cluster, i'm not 100% positive but that sounds like it should work.

on the coil/ignitor, no i'm not 100% sure. about 70%. hehehe (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/006_grin.gif) if you try it and it works lemme know. i didn't try it, a friend did and relayed the info to me.

frankie

[fos240]

bump for the other thread.

frankie

[fos240]

is there anyway this can be pinned? i've had a couple people ask me in the last couple of days.

thanks,
frankie

[planb]

oh, by the way, the SOHC and DOHC ignitors/coils are interchangable. My friend is using a SOHC one on his DOHC swap! the coil uses a different size wiring plug between SOHC and DOHC, so you just have to splice in the correct one.

[fos240]

cool. (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/emthup.gif) i've been wondering about that every since you mentioned it the first time. i've also been curious about the mafs. the plug comes out at a different angle, but the connector still fits. i wonder if those are interchangeable as well? might have to do some experimentation on Biggie's car. (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/044_fear.gif)

frankie

[planb]

cool. (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/emthup.gif) i've been wondering about that every since you mentioned it the first time. i've also been curious about the mafs. the plug comes out at a different angle, but the connector still fits. i wonder if those are interchangeable as well? might have to do some experimentation on Biggie's car. (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/044_fear.gif)

frankie

Im 99% sure the mafs arent interchangable. I know you can do some rewiring and get a SOHC maf to work on a SR, but not a DOHC maf.

mafs are (IMG:http://www.carolinanissans.com/forums/style_emoticons/default/036_wacko.gif)

[90bluegsturbo]

question, i drive a 97 hardbody. is it possible for me to swap the k24e to the k24de motor from a 95-96 hardbody? i have the bottom end for it but i am wanting to gohead and rebuild it and see what can be done with it. i figured put it into my truck and install a turbo system after i put some arias pistons and wiesco rods in it!

let me know what you guys think of this!

remember be nice im a nissan newb but i know how to work on cars i have a gst as my weekend rice killer ;-)

[drewmc]

I tried to search if s14 motor mounts wil fit in a s13 car or are they the same mounts?

[JDS_Performance]

I tried to search if s14 motor mounts wil fit in a s13 car or are they the same mounts?

same motor mounts between s13 & s14 - tranny mounts are the same too

[biggie]

I tried to search if s14 motor mounts wil fit in a s13 car or are they the same mounts?

Same.

[fos240]

I tried to search if s14 motor mounts wil fit in a s13 car or are they the same mounts?

same motor mounts between s13 & s14 - tranny mounts are different though

that is incorrect sir. (IMG:style_emoticons/default/001_smile.gif) there are 3 different tranny crossmembers stamped A, B, and C. but the tranny mount itself is the same.

frankie

[PSi]

The SOHC accel. cable can be used but it will nt sit in the stock location anymore... Just an FYI... I do it because im cheap and see no reason to swap cables when i can me the original SOHC cable work...

-PSi

[fos240]

The SOHC accel. cable can be used but it will nt sit in the stock location anymore... Just an FYI... I do it because im cheap and see no reason to swap cables when i can me the original SOHC cable work...

-PSi

it looks like shit when you have the cable laying across the engine. plus, when i tried to make it work, it held the throttle body open. couldn't get around that.

frankie

[2Fass240us]

THIS THREAD HAS BEEN EDITED TO REMOVE ALL RECENT OT MATERIAL.

BTW, pinned tech threads are the worst to crap on. Please take note.

[HIF|13]

The SOHC accel. cable can be used but it will nt sit in the stock location anymore... Just an FYI... I do it because im cheap and see no reason to swap cables when i can me the original SOHC cable work...

-PSi

it looks like shit when you have the cable laying across the engine. plus, when i tried to make it work, it held the throttle body open. couldn't get around that.

frankie

i had the SOHC throttle cable on my DOHC swap. Yes it did look crappy resting on the valve cover... but it did work. i had no problems with it keeping the throttle open. anyone trying to get away with using the SOHC cable... it's worth a shot.

[fos240]

did you happen to look and see if the throttle plate would open all the way when the pedal was fully pressed? i know the sohc has a shorter length both on liner and the internal cable. when i tried it, it held the throttle open even at rest. if the cable could be adjusted far enough to close, i don't think it would open the throttle plate all the way because the cable would run out. i dunno. maybe some of the DOHC had smaller cable holder-opener thingys. (i forget what they are called.) or better yet, maybe some people are putting them on the opener that the cruise control actuator goes to. i think those might be smaller. or maybe s14 openers are larger. i was using a s14 engine that didn't have the cruise control opener with it.

frankie

[HIF|13]

well mine was a s13 DOHC non-cruise control... and the throttle did open all the way.

[lackeydog]

I was told the dohc and soch trans were the same, is this true?

[biggie]

I was told the dohc and soch trans were the same, is this true?

For 5 speed S13 purposes, yes.

[lackeydog]

Thanks man

[Chris28]

What is the difference between the s13 and s14 ps pumps? I'm running a 96 engine in my 92 and I'm still using the s13 lines. Where it bolts into the pump was leaking a little bit but I tightened it up and it stopped leaking. I'm wondering if this is why it was leaking and if I should put on my s13 ps pump. Thanks.

-Chris