Sohc Vs Dohc

[The ROMAN]

I'm in the market for a S13 240sx and there seems to be a lot more 89-90 240's than 91-93 240's and I was wondering how much difference and the DOHC engine makes.

[240Dave]

IIRC it's about a 10hp/10tq difference, the DOHC having the higher rating of ~155hp/~160tq.

From everything I've read, the SOHC has a better head design and as a result is more responsive to n/a tuning. I'm not sure at what level it begins to pay off though...

[Andy5]

I thought sohc had a hp rating of 130/150 maybe i'm wrong, but i raced an s14 and it owned me so. dohc is a more powerful motor I beleave and from what I have seen. I'd go DOHC if u plan on KAT, i'd stay w/ a SOHC if u go N/A, i hear good things about n/a sohc motors.

But thats just my experince, i'm sure an hour of seraching on google could answer the question better than me :)

[KiDyNomiTe]

You lost cuz your shitty driver :p

SOHC is "slower", but that would only showin the year 90 if you bought a '91 240 and raced a '90. 10+ years later so much could have gone wrong with these motors that the DOHC could be slower with equal drivers. If its taken care of, its a drivers race with the DOHC having a slight edge.

And ya NA SOHCs seem to do a lot better, but I guess they have more products out there cuz they came in trucks and truck owners tend to build NA if they build thier motors at all.

Get whatever is in better condition body and suspension wise if you plan on SR. There is less that you can replace with the body, or it will add up to be a lot more, than if you just get shit motor.

[Andy5]

sh*tty driver? ya possibly :D But i nail'd every shift, I was acutally ahead, his lights were at my door till about 3rd then he walked up and left. but then agian i have 220k on my SOHC hehe I bet he barely had 100k. I give credit to my motor for taking the beating and holding up well. :P the piston rings are worn down and it burns oil, but as soon as i get the cash i'm gonna drop a dohc in it.

I wouldn't single out the sohc though, it can be a mean motor, espiecally if u build it right. =) Don't make ur mind up on something you haven't tried.

[AceInHole]

Originally posted by 240Dave
IIRC it's about a 10hp/10tq difference, the DOHC having the higher rating of ~155hp/~160tq.

From everything I've read, the SOHC has a better head design and as a result is more responsive to n/a tuning. I'm not sure at what level it begins to pay off though...

nah... SOHC doesn't "really" have a better head design. NASPORT (the form of road racing that 240sx's seem to have been "popular" for) doesn't allow DOHC engines, so all the cars used SOHC engines, resulting in more products made for the SOHC engine initially, making it a "wiser" choice for the NA route. I'm not so sure that this stands true anymore, since now cams, cam gears, ITB's, etc. have been made for the DOHC engine.

[X1nom3D]

well, i own a sohc, and i spank a bunch of dohc before. but now all my friends have the sr20 in it, haha, cheaters! ask me and i'll tell you a bunch of good things about my sohc, haha.

[sykikchimp]

I used to have a SOHC 240.. I blew the engine, replaced it with a rebuilt one, and it was still slower than my DOHC.. actually, it was slower than my girlfriends Saturn too.. :cry:

I'm glad I have the DOHC engine.

There's more aftermarket for the 91+ cars too..

[THX1138]

actually, it was slower than my girlfriends Saturn too..

And now your girlfriend has a Spec V...

[sykikchimp]

Originally posted by THX1138
And now your girlfriend has a Spec V...

which totally kicks my DOHC's ass.. as you witnessed numerous times. :bash: LOL

...i need turbo...

[andrave]

there is greater support for the ka24e to go NA and greater support for the DE to go turbo.
there is support for each engine either way you choose to go, but as far as the easiest/cheapest/best parts for each engine, the above is a generalization.
The ka24E was actually used in the hardbodys to compete in truck racing (just like the 2.3 liter ford engine also used in 4 cyl mustangs/rangers/countless others) and that is where a lot of the NA performance parts came from.
But anyway, they both have their advantages, stock for stock a dohc is better but if you are rebuilding them its not gonna matter much.