Heyas guys,

I want to swap a ZC in my crx, then put intake and 2.5 Exaust, Then turbo around 5 psi. What are the advantages to disadvantages of SOHC vs DOHC for boosting. Are there any problems or benefits of either?

Ive looked up specs and prices

SOHC has about:
9.1 CR
119 hp
105 lb/ft
$390

DOHC has about:
9.6 CR
129 hp
106 lb/ft
$525

$135 = 10 more hp and 1 more torque...

What do you think?
~AMH

 

dohc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sekz &raquo;</TD></TR><TR><TD CLASS="quote">dohc.</TD></TR></TABLE>

 

ttt

 

DOHC

knew guy running 12s with a boosted DOCH on street tires

i think the DOHC ZC is underrated as swap real peppy and cheap

 

I have a DOHC ZC with a turbo. The motor has held up really well over the last few years with me driving it hard and racing it a few times a year. It certainly isn't the be all end all, but it is fun as hell to drive every day. You don't have a problem passing, merging, etc... that's for sure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by therealciviczc &raquo;</TD></TR><TR><TD CLASS="quote">I have a DOHC ZC with a turbo. The motor has held up really well over the last few years with me driving it hard and racing it a few times a year. It certainly isn't the be all end all, but it is fun as hell to drive every day. You don't have a problem passing, merging, etc... that's for sure.

</TD></TR></TABLE>

sorry i'm not trying to jack ur thread man, but i just picked up a y7 w/ 57k, but i was thinking the same thing..... stay w/ my soch or pic up a dohc? i've heard good and bad things about the dohc zc motors that why i just bought the y7..... where do you all get you dohc zc's from?

again i'm sorry i don't mean to jack ur thread....

 

no thats fine whitey, I could use some of the awnswers to your questions too. Also, like posted in the org thread, does anyone know the advantages to disadvantages to dohc vs sohc?

thanks
~AMH

 

Well the DOHC is just that, a DOHC ZC. A SOHC ZC is just an A6, so your pick. I would personally start with the DOHC if I was presented with the choice.

 

The DOHC ZC has bigger ports, more OVERALL FLOW
the SOHC ZC has smaller ports, more velocity
But since you're only Boostin 5 psi, go with the SOHC ZC
why?
parts are the same as D16A6 which are more plentiful,
Lower C.R. for a bigger window for tuning error, and u can also source D15's for a head, which are MORE the plentiful
plus Turbo install needs some room in the front engine bay, something the DOHC kinda uses up.
it's still very possible to Turbo the DOHC though

I put together a Quasi D16A6 for $40 by sourcing other peoples JUNK
still runs hard in my friends hatch with 50 shot.

 

So what im getting is this?

reasons to turbo sohc:

more plentiful parts, lower CR, and more room in the front of engine bay for turbo.

reasons to turbo dohc: more power


can anyone add anything to this?

~AMH

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HumanResource &raquo;</TD></TR><TR><TD CLASS="quote">The DOHC ZC has bigger ports, more OVERALL FLOW
the SOHC ZC has smaller ports, more velocity
But since you're only Boostin 5 psi, go with the SOHC ZC
why?
parts are the same as D16A6 which are more plentiful,
Lower C.R. for a bigger window for tuning error, and u can also source D15's for a head, which are MORE the plentiful
plus Turbo install needs some room in the front engine bay, something the DOHC kinda uses up.
it's still very possible to Turbo the DOHC though

</TD></TR></TABLE>

so assuming you go with the dohc zc, because of better tunning w/ d. cams, and more hp + tq....... what's gonna happen when you up the boost to maybe 8 or 10psi ( because those of you who boost know you want more than what you have most of the time) do the make aftermarket head studs and what not as to not blow the head gasket and what not? or can it handle it? are they the same as using the a6 bolts?

if the sohc zc is used, how does it compare hp + tq wise? will a dohc zc-T blow the sohc zc-T away or will it be close? whats would the better investment be? for the long run?

DOHC ZC= more hp + tq from the start.....
SOHC ZC= more aftermarket parts.....

*thanks again amh0001 for letting me jump in on this well needed info*

 

SOHC

 

I would go with the DOHC.

(1) the more HP you start with the more you can make with a a turbo at the same levels of boost.

(2) easier to tune

(3) There are cams, rod, pistons, valve springs, etc for making the engine even better.

Check out these sites for the aformementioned stuff:
http://www.buy-efi.com/
http://www.jgenginedynamics.com/

 

Some quick stuff.

The lower CR allows you more margin of error with tuning, while the higher CR allows you to achieve a higher horsepower/torque with less boost.

The lower cost of the SOHC could be used towards some nicer things, such as B rods with Suzuki forged pistons.

You could also live more on the dangerous side with the SOHC if you wanted to, such as mini-me with boost!

 

FYI....Suzuki forged pistons.... ARE NOT FORGED !!!!!!!!!!!!!!do some more research........

 

go with the dohc zc for boost. if ur worried about cr get a thicker headgasket. and u will have the same amount of room in the engine bay with a dohc zc compared to a sohc. either way id prob get the motor thats easier to find and is cheaper.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by julio_bOostamante &raquo;</TD></TR><TR><TD CLASS="quote">FYI....Suzuki forged pistons.... ARE NOT FORGED !!!!!!!!!!!!!!do some more research........
</TD></TR></TABLE>

Whoops, your right.

I should have said, heat treated aftermarket Suzuki pistons.

 

thats a lot of really good information!!! i know it's helping me with my choice so thanks to everyone that awnsered my questions also... AND most of all thank you amh0001 for letting me jump in on your thread!!

 

Haha,

no, thank you, you summed up what I was trying to ask.

~AMH

 

In all reality it doesnt matter too much, stock to stock go with dohc but once you start modding the motor for turbo you replace most of what the differences are. Plus the dohc/sohc tuning possibilities can only be used if you buy adjustable cam gears....and the cheapest I've seen for the dohc zc are like $300+, sohc you can get for $75. Not to mention if you blow somethin on the sohc theres a ton of other motors than have interchangeble parts....thats the main advantage over the dohc. But I love my sohc.

 

I'm gonna be different and say the SOHC!

SIKE!!!!!!

Dude, go with the DOHC, for the high tunability, and the increased flow of 4 valves instead of two per cylinder!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin_Bradley &raquo;</TD></TR><TR><TD CLASS="quote">
Dude, go with the DOHC, for the high tunability, and the increased flow of 4 valves instead of two per cylinder!</TD></TR></TABLE>

Both are a 16v head Dude, SO its 4v per

But I'm a big fan of a Mini me turbo good stuff, you can Build a Mini me for what your going to spend on a DOHC ZC. Then you have around the same HP and tq numbers as a DOHC ZC. Thats my .02

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin_Bradley &raquo;</TD></TR><TR><TD CLASS="quote">Dude, go with the DOHC, for the high tunability, and the increased flow of 4 valves instead of two per cylinder!</TD></TR></TABLE>

SInce when is the A6/SOHC ZC an 8 valve motor?!?

Alex