SOHC to DOHC - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Tygma · 05-31-2004, 12:34 AM

ok so my sohc is dying, and i honestly dont want to put any money into it. i dont think i want to go with SR... lack of funds, for now. I was trying to find a good condition dohc but im just curious on what is necessary on the swap? My motor plans are very vague for now, just trying to gather information on a few ideas i had. Thanks a lot.

240Driver39 · 05-31-2004, 02:00 AM

theres a very good post in the archive section regarding this..and since im nice..here ya go man

http://www.zilvia.net/f/showthread.php?t=33502

its a good place to start.

Tygma · 05-31-2004, 05:25 PM

thanks a lot...
wow seems like a lot to do! its certainly my option if im limited on cash, but i mean.. since its replacing a whole heck of a lot, i should just go with a CA or SR then huh. i really cannot make up mind.

mjjstang · 05-31-2004, 07:12 PM

dude, dohc only gets you what 10 hp, not much. either bight the bullet and do sr or stick w a direct swap sohc, warning sr is gonna be pretty expensive. ive been saving up for like a year now and still need tons of shit.

stinky_180 · 05-31-2004, 07:27 PM

i just finished my friends install of sohc to dohc, first time without a lot of help and good tools.

parts needed:
dohc wiring harness (uncut is easier)
dohc ecu (get ecu that is designed for your tranny
motor
upper radiator hose
dohc intake tube

maf and ignitor (dependso on what you wanna do)

thats basically what you need and some modification to get other things to work.

the dash wiring harness will not work with the ka24de wiring harness, but you can do some splicing of your own. get your sohc wiring harness, cut the middle of all the wires that connect to your dash harness, plut that sohc connector (one that you just cut from your old harness) and splice it with the dohc wiring harness, match all the colors, theres a few wires that wont match up, so just cap those and hide them somewhere for a clean look.

sohc maf/afm and ignitor wont connect to the dohc wiring harness. so you can either source the dohc maf/afm from a junk yard, forums (i found plenty of these on www.freshalloy.com) or you can cut your dohc wiring harness and use your sohc harness, just like you did with the dash harness. do the same for the ignitor.

sohc upper radiator hose gets in the way of the sohc intake tube. so you can either make your own custom intake or use the dohc intake tube, if you use the dohc intake tube, get the upper radiator as well.

power steering bolt up directly so you have to modify it yourself, (not sure where you can do that or how you can as i am still trying to figure something out).

and if you drifted your sohc 240 its a good thing to replace your clutch (if not new) and flywheel. i've been told that the sohc flywheel can't support the 30+ hp increase, but i'm not sure, anyone can confirm this? kthnx.

i think thats about it, you'll love dohc motor compared the the sohc motor (atleast some people). its easier to break loose than the sohc.

oh yea one more thing, 91-93 ka24de have the better cams (247 degrees i believe) compared to the other s14 ka24de.

and if you have free time and still sourcing out parts, you should replace the head gasket, port the intake a little bit, take out the secondary butterfly from the intake tract (upper part of the intake). clean the engine and what not.

have fun with the dohc motor ^^

ps. i'm new to this forum. foudn out abotu this forum through my friend mansoor.... if you went to that tustin market pl. meet on may 30th, i was the green fastback that no one talked to ^^....

stinky_180 · 05-31-2004, 07:29 PM

Quote:

Originally Posted by mjjstang

dude, dohc only gets you what 10 hp, not much. either bight the bullet and do sr or stick w a direct swap sohc, warning sr is gonna be pretty expensive. ive been saving up for like a year now and still need tons of shit.

some people dont have money, and its 30 or so hp. and its a learning experience when swapping an engine that is cheap.

mjjstang · 05-31-2004, 08:30 PM

so im saying if you dont have the money stick to the kae, and also I learned all I needed to learn by just swapping my friends ka for another ka of the same variety and im doin alright. all signs point to the kae

FastBack 240 · 05-31-2004, 08:54 PM

Good luck finding a low milage SOHC but thats your best bet.

Tygma · 05-31-2004, 09:51 PM

sucks because some of think that since i only have 27 posts that im a noob. anyhoooooooooooooooo.. im aware of the gains of the dohc, im not going for anything extreme, shieet. my sohc's timing chain guides are fucked, and i really dont want to replace them (replaced freinds and it was well over 10+hours of labor!) it has high mileage, and blah blah blah. so i'd rather do something that will.. a. Pass smog b. be realiable c. be cheap to purchase and maintain. im aware of pricing for the SR and the CA (of course CA parts isnt AS much as the SR) but i can get a front clip for 2200. thats not including the upkeep and not the 250 to pass it for smog. I also wouldnt like my hood to be popped by some lame-o cop. finding a low-mileage KAe or de would be ideal for me i guess, and thanks for those who contributed to my decision. Now, is there anyone in Norcal willing to help me out with the swap?

yacho7 · 05-31-2004, 11:30 PM

Quote:

Originally Posted by FastBack 240

Good luck finding a low milage SOHC but thats your best bet.

Ricer240sx · 06-01-2004, 12:59 AM

thanx guys for the info, i too am gunna do this casue i got a DE-T sittin at my buddies house waitng to go in and i am picking up a 89 hehehe

05-31-2004, 12:34 AM	#1
Tygma Zilvia Addict Join Date: May 2004 Location: Bay Area Posts: 965 Trader Rating: (0) Feedback Score: 0 reviews	SOHC to DOHC ok so my sohc is dying, and i honestly dont want to put any money into it. i dont think i want to go with SR... lack of funds, for now. I was trying to find a good condition dohc but im just curious on what is necessary on the swap? My motor plans are very vague for now, just trying to gather information on a few ideas i had. Thanks a lot. __________________ My review forum

05-31-2004, 02:00 AM	#2
240Driver39 Zilvia FREAK! Join Date: May 2002 Location: Charleston, SC Age: 40 Posts: 1,090 Trader Rating: (1) Rides Gallery: 240Driver39 Feedback Score: 1 reviews	theres a very good post in the archive section regarding this..and since im nice..here ya go man http://www.zilvia.net/f/showthread.php?t=33502 its a good place to start. __________________ 1990 240sx 5spd fastback

05-31-2004, 05:25 PM	#3
Tygma Zilvia Addict Join Date: May 2004 Location: Bay Area Posts: 965 Trader Rating: (0) Feedback Score: 0 reviews	thanks a lot... wow seems like a lot to do! its certainly my option if im limited on cash, but i mean.. since its replacing a whole heck of a lot, i should just go with a CA or SR then huh. i really cannot make up mind. __________________ My review forum

05-31-2004, 07:12 PM	#4
mjjstang Post Whore! Join Date: Apr 2003 Location: Michigan Posts: 2,654 Trader Rating: (5) Feedback Score: 5 reviews	dude, dohc only gets you what 10 hp, not much. either bight the bullet and do sr or stick w a direct swap sohc, warning sr is gonna be pretty expensive. ive been saving up for like a year now and still need tons of shit. __________________ I was going to, but I can not think of a sig less than 75 characters.

05-31-2004, 07:27 PM	#5
stinky_180 Nissanaholic! Join Date: May 2004 Location: Pale Blue Dot Age: 40 Posts: 2,064 Trader Rating: (26) Feedback Score: 26 reviews	i just finished my friends install of sohc to dohc, first time without a lot of help and good tools. parts needed: dohc wiring harness (uncut is easier) dohc ecu (get ecu that is designed for your tranny motor upper radiator hose dohc intake tube maf and ignitor (dependso on what you wanna do) thats basically what you need and some modification to get other things to work. the dash wiring harness will not work with the ka24de wiring harness, but you can do some splicing of your own. get your sohc wiring harness, cut the middle of all the wires that connect to your dash harness, plut that sohc connector (one that you just cut from your old harness) and splice it with the dohc wiring harness, match all the colors, theres a few wires that wont match up, so just cap those and hide them somewhere for a clean look. sohc maf/afm and ignitor wont connect to the dohc wiring harness. so you can either source the dohc maf/afm from a junk yard, forums (i found plenty of these on www.freshalloy.com) or you can cut your dohc wiring harness and use your sohc harness, just like you did with the dash harness. do the same for the ignitor. sohc upper radiator hose gets in the way of the sohc intake tube. so you can either make your own custom intake or use the dohc intake tube, if you use the dohc intake tube, get the upper radiator as well. power steering bolt up directly so you have to modify it yourself, (not sure where you can do that or how you can as i am still trying to figure something out). and if you drifted your sohc 240 its a good thing to replace your clutch (if not new) and flywheel. i've been told that the sohc flywheel can't support the 30+ hp increase, but i'm not sure, anyone can confirm this? kthnx. i think thats about it, you'll love dohc motor compared the the sohc motor (atleast some people). its easier to break loose than the sohc. oh yea one more thing, 91-93 ka24de have the better cams (247 degrees i believe) compared to the other s14 ka24de. and if you have free time and still sourcing out parts, you should replace the head gasket, port the intake a little bit, take out the secondary butterfly from the intake tract (upper part of the intake). clean the engine and what not. have fun with the dohc motor ^^ ps. i'm new to this forum. foudn out abotu this forum through my friend mansoor.... if you went to that tustin market pl. meet on may 30th, i was the green fastback that no one talked to ^^.... __________________ SoCal RallyX Coverage and MTB Ride Reports WheelsDirty

05-31-2004, 08:30 PM	#7
mjjstang Post Whore! Join Date: Apr 2003 Location: Michigan Posts: 2,654 Trader Rating: (5) Feedback Score: 5 reviews	so im saying if you dont have the money stick to the kae, and also I learned all I needed to learn by just swapping my friends ka for another ka of the same variety and im doin alright. all signs point to the kae __________________ I was going to, but I can not think of a sig less than 75 characters.

05-31-2004, 08:54 PM	#8
FastBack 240 Zilvia Addict Join Date: Dec 2002 Location: Motor City......MI Age: 39 Posts: 859 Trader Rating: (0) Feedback Score: 0 reviews	Good luck finding a low milage SOHC but thats your best bet. __________________

05-31-2004, 09:51 PM	#9
Tygma Zilvia Addict Join Date: May 2004 Location: Bay Area Posts: 965 Trader Rating: (0) Feedback Score: 0 reviews	sucks because some of think that since i only have 27 posts that im a noob. anyhoooooooooooooooo.. im aware of the gains of the dohc, im not going for anything extreme, shieet. my sohc's timing chain guides are fucked, and i really dont want to replace them (replaced freinds and it was well over 10+hours of labor!) it has high mileage, and blah blah blah. so i'd rather do something that will.. a. Pass smog b. be realiable c. be cheap to purchase and maintain. im aware of pricing for the SR and the CA (of course CA parts isnt AS much as the SR) but i can get a front clip for 2200. thats not including the upkeep and not the 250 to pass it for smog. I also wouldnt like my hood to be popped by some lame-o cop. finding a low-mileage KAe or de would be ideal for me i guess, and thanks for those who contributed to my decision. Now, is there anyone in Norcal willing to help me out with the swap? __________________ My review forum

06-01-2004, 12:59 AM	#11
Ricer240sx Zilvia Addict Join Date: Sep 2002 Location: Green Bay WI Age: 40 Posts: 615 Trader Rating: (0) Feedback Score: 0 reviews	thanx guys for the info, i too am gunna do this casue i got a DE-T sittin at my buddies house waitng to go in and i am picking up a 89 hehehe __________________ 00 impreza 2.5rs sedan...dd 00 impreza 2.5rs coupe....EJ255, goin rwd!!