Okay I've been on the board for years now, and I've seen God knows how many of the same topics before. I'm sure I've even taken part in a few SOHC vs. DOHC ZC topics, but this time I'm asking for a good friend whose situation is a bit different than some of the past topics. Do me a favor and please do not reply if you cannot contribute anything positive to the topic at hand. If you hate the topic, please close the window and move along.

Oh and also I couldn't even seach for "ZC" in our wonderful H-T search engine because it's "too short" so again please help if you can, move on if you can't or don't feel like it.

My friend picked up a pretty nice 1989 LX 4-door with the seatbelts in the car (lighter chassis) for the sole purpose of swapping an engine into it and making it a fun weekend auto-Xer, daily driver with some *****. He got his inspiration from my 1990 EF when I built an 11:1CR D16A6, so he's stuck on the D-series.

A few ground rules for the topic:

1. He cannot go B-Series - period. His budget will not allow for a B series, and he also doesn't want the crazy vibration from the mount kits that you have to run with a B series either. He also wants to keep A/C, P/S, and doing so with a B series costs more and is more of a PITA.

2. He's not going boost. He is an N/A guy more so, and he knows that he cannot afford another block or parts if he blows his up on boost.

3. We live in GA where DOHC ZC engines are hard as **** to get from reputable sources here. We can get SOHC ZC engines all day long. The SOHC ZC is only a few hundred dollars cheaper, but they ar also abundant. Our engine source offers a 6 month, unlimited mileage warranty. They tell us that they can probably find one DOHC version and have it trucked in. Keep this in mind...

Having said that here are the choices:

SOHC ZC, non-VTEC
DOHC ZC

Which one would you choose, and why?

Now some N/A mods are not out of the question here, but it won't be anything like I did like stuffing high dome pistons in the block or anything. At most I'm thinking a good cam or cams and valvetrain. Obviously if he got the SOHC he could drop a good cam in it immediately.

I've already PM'd Wil at Exospeed asking his opinion, but I'm waiting for a reply.

Thoughts from experience would be great. I have a few ideas on this myself, but I'm curious as to what you guys think.

EDIT:

Dyno charts for DOHC ZCs with bolt-ons and possibly cams and dyno charts from SOHC ZC engines or stock-block D16A6 engines with bolt-ons and a good cam would be awesome too!

 

well i have no experience with the sohc zc, but i had a d16a6 in my last hatchback with a milled head and p&p'ed with d16a1 pistons for higher compression. I now have a 13 year old dual cam zc in my new hatch and the zc is the same if not a little bit faster. I have an lsd tranny on my zc now so maybe thats why it feels a lot faster, but the d16a6 had work done to it. I would personally go with a good engine importer and get a dual cam zc engine in it. gotta love the roar of a dual cam.

Cliff Notes: Pick the dual cam zc

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red_Si &raquo;</TD></TR><TR><TD CLASS="quote">well i have no experience with the sohc zc, but i had a d16a6 in my last hatchback with a milled head and p&p'ed with d16a1 pistons for higher compression. I now have a 13 year old dual cam zc in my new hatch and the zc is the same if not a little bit faster. I have an lsd tranny on my zc now so maybe thats why it feels a lot faster, but the d16a6 had work done to it. I would personally go with a good engine importer and get a dual cam zc engine in it. gotta love the roar of a dual cam.

Cliff Notes: Pick the dual cam zc</TD></TR></TABLE>

So did you have the flat top 86-87 A1 pistons, or the 88-89 high dome pistons?

Also what tranny was on the worked A6.

Just curious.

 

B18C5-EH2
I feel you on the "ZC" search, and I'm hoping as the time goes by people will refer to it as the DOHCZC which should make it a little more easier to research.

I'm gonna give you a heads up on Wil's response, cuz i did ask him the same question a while back.
something like "I personally prefer the SOHC...more parts availability...more experience with the SOHC"
and "Haven't had equally the same amount of experience with the DOHC...still a good engine"

I ended up going SOHC ZC for that exact same reason
If you look at the engine specs side by side, the DOHC ZC wins with Higher C/R, DOHC design, bigger valves, more aggressive cams and better flowing Int Mani
BUT I'm here in Cali where smog laws are

I did have a B16 in my old hatch and dreaded getting pulled over (let's not get into the idiot politics involved) but if you're in an area with **** pigs that have surprise Roadside smog checks then this is something to consider with the DOHC ZC.

With my current SOHC ZC with IHE, EXOSPEED SR909 cam and PM7 ECU I can EASILY say I'm faster than a stock DOHC,
Sure you can upgrade the DOHC just the same and probably tune it to net more power than my SOHC, but it's nice to know when if I get pulled over they won't find CHIT!!!

As far as the part availability, the SOHC simply OWNS
for example, the distributor you can rely on 88-91 CIVIC/CRX Si AND HF models as well as 90-91 Civic EX models aside from the JDM units which are the same.
The DOHC only 88-89 Integ Units

The the SOHC HEAD- should anything unholy happen to yours you can source the D15B 16V units which are a dime a dozen.

Head gaskets- you can use the Y8 metal units and get more C/R
DOHC ZC- stock composite covered OR aftermarket units (like Cometic)

Intake Manifolds - the SOHCs are lucky to have OEM upgrades like the Y8 unit
where the DOHC has a unique bolt pattern that can only be switched out with D16A1 units. No upgrade is needed on the DOHC piece anyway since it's design looks good so this part I GUESS is no winner no loser.

EXH Manifold-same No winner no loser since they use the same bolt pattern.

If your friend is NOT going to be doing any major upgrades internally and will be limited to BOLT-ONS, I would go SOHC ZC

the DOHC ZC is NICE but the SOHC much more practical.

Now, let's wait for the sumbtchs that hafta add on stupid non related posts like "neither go B16", or " I'd GO H22 and run 10's all day"

 

Today I am moving a sohc zc into my basement, to rebuild with some other stock Honda parts. I know from having that sohc zc in my car that it DID pull more than the stock d16a6 (as per the g-tec pro) I am going to pull apart the head and measure deck clearance, combustion chamber, cam lobes, and valve sizes. Hopefully this will determine why the zc does pull harder.

I think the zc head with the 88-89 high domed pistons and a p&p will be a formidable sohc longblock, along with a bored TB, port matched intake/exhaust mani, and free flowing intake and exhaust ....you will have a sohc that will run the 1/4 near a b16 swap. Swap in an exospeed hot cam...and I would almost guarantee it.

Ill use this post to document my findings.

-Jake

 

A freind of mine ran both motors in his car. The car ran better with the SOHC ZC motor. But I have heard the other way around from other people, that there DOHC ran better. I guess its a matter of the motor you get, and how well it runs.

Why hasnt he given any thought to a z6 swap? Its not to much more and it runs like a champ It cant be to far out of his budget, I picked up my z6 motor for 150 bucks

Well anyhow good luck to your freind

 

Ive got a sohc, I actually bought a DOHC form the company but they sent me a SOHC and 25% of my money back because they messed up.

Ive done I/H/E/Gutted cat/PG7 Ecu and a Zex 65 dry shot

Holds wonderfly and beats B series swapped cars with a passion

Great reliable motor but I will be going B series with the next CRX

 

I would say the sohc zc since he doesn't want to do any major internal upgrades, the dohc zc has everything available for it except the valvesprings, but you can do the ls spring upgrade on that, but that same amount of money to do that conversion could be better put to use in the sohc zc.

 

With a tune - up , I/H stock exhaust and 26 psi tires I lost to both a 99 GSR and a 94 GSR by 2 cars(Both had AEM V2s). In my opinion the dual cam zc is a pretty stout motor. I've driven both and I think the DOHC seems to pick up alittle faster, maybe due to the 9.5:1 compression ratio. Yes, the DOHC ZC is a bit wierd due to mix - matched parts. But I got mine for $100 bucks more than the SOHC and I've put tracks all over the SOHC with the same mods. I would say it depends on the person, of course a SOHC owner will swear his is faster, and a DOHC owner will swear by his also. But since you say the SOHC is readily availible and it seems his pocket is like the shallow end of a kiddy pool, I would recommend the SOHC assassin. - Darrell
ps: I believe the SOHC is a bit lighter and easier to work on since the DOHC is squeezed into that ebay.. (my DC Ceramic 4 - 2 - 1 hits my radiator fan housing.)

 

i'm not too knowledged as a few of you guys that posted, but i did heard that the sohc has more torque. if that is so, that is another point to consider.

 

I have a D16y8 in my 91 Si hatch, I have yet to run it because I just bought it a week ago. The motor was already in the car when I bought it. I think 1st & 2nd gear the car is awesome it pics up well. The top end tho I am not happy with, the car has I/H no exhaust, Vtec controller. I want to build the motor for better top end.

any suggestions sorry to HI JACK the thread

 

hey i got a built jdmdohc zc for sale i am in san jose california. let me know if u are still looking for one. pm me and i can tell you what it has on it

 

Thanks for the replies thus far; they are appreciated.

As far as his budget goes, he can afford the DOHC ZC also. It's only a few hundred more than the SOHC. This topic is mainly to see who likes the SOHC vs. DOHC and why.

It looks like the SOHC is winning thus far - where are the DOHC heads?

BTW:

Remember that building the bottom end is out of the question. Again if he had the time, money, patience, and didn't mind taking the risk he'd be doing a D16A6 with P29 pistons just like I did since mine runs like a champ. It's basically DOHC vs. SOHC with the mods being i/h/e and possibly a good cam or cams.

Let's see some battles y0!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Harry_Randal &raquo;</TD></TR><TR><TD CLASS="quote">
Why hasnt he given any thought to a z6 swap? Its not to much more and it runs like a champ It cant be to far out of his budget, I picked up my z6 motor for 150 bucks
</TD></TR></TABLE>

The Z6 requires more wiring and it's simply to much of a PITA in my opinion. Him not wanting a SOHC VTEC engine is probably the same reason why I won't add a VTEC head to my A6 bottom end either - I've never experienced a SOHC VTEC engine that runs worth a damn in an EF chassis.

I'm all about the D16Z6 though - my old stock 1992 Si HB with only mod being an AEM intake ran a 15.6 in the 1/4 mile even with full interior! The car weighed like 2260lbs. and was even stock ride height on **** Michelin tires too. That car ran awesome for what it was.

Basically again it's SOHC non-VTEC ZC vs. DOHC ZC.

 

B18C5-EH2, Have you DYNO'D your D16A6???
I've seen your similar set ups like yours (sans the trick gearbox) run some pretty impressive times at the track.
HAVE YET TO SEE THIS SET-UP DYNO'D!

 

DOHC all the way...

i dont know why everyone is pumping up the sohc, when u do the same mods to the DOHC it will rip WAY harder, its common knowlage ur runnign 2 cams and beefier valvetrain on top of that . But one thing i can relte to is that all engine are not created equal, this is especially true with JDM engines, i have had some DOHC's that ran extremly well, and some that just fell on their face (comp was low lack of maintnence on the JDM side). So thats why some people are going with teh sohc's becasue for teh most part i think the DOHC's got a beating when they were in JDM land. Besides all this i hit a 14.9 (cheep street tires)-(same as my old b16 hatch, just MPH was lower with the ZC) with a DOHC ZC with slight mods. The block was complete stock head was milled, custom port work/valve job rigged up port matched b16 manifold (welded the 2 manifolds together) HKS cams and bored 00 SI TB (62mm) not more then 500 bucks in parts. I ran open header and on the MUGEN chip for the pm6. Side note: any engine u run, run with the Mugen for the PM6/7 it rips hard. I had goo results and for not much cash so i am with the DOHC

i ran a a6 with just about everything i had listed with y8 manifold. the car ran strong but it didnt have as much pull as the DOHC, and it was missing alot of mid-range torque that the dohc had .

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">The Z6 requires more wiring and it's simply to much of a PITA in my opinion. Him not wanting a SOHC VTEC engine is probably the same reason why I won't add a VTEC head to my A6 bottom end either - I've never experienced a SOHC VTEC engine that runs worth a damn in an EF chassis.

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

u never ran in my z6 CRX hatch before i was boosting , with less mods then i did to the DOHC ZC it felt alot stronger and liked hi revs . And theres not much more wiring for the z6, all u need is 2 more wires and one ground to run, is it that much?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nerologic &raquo;</TD></TR><TR><TD CLASS="quote">
u never ran in my z6 CRX hatch before i was boosting , with less mods then i did to the DOHC ZC it felt alot stronger and liked hi revs . And theres not much more wiring for the z6, all u need is 2 more wires and one ground to run, is it that much? </TD></TR></TABLE>

Actually you either convert the car to OBD1 (not fun) or you have to ghetto rig the pre-OBD stuff in terms of notching out the timing slots and hacking a leg off the pre-OBD distributor, running VTEC with a pre-OBD SOHC ECU and some sort of VTEC controller/activator, etc.

It IS more work, and I've still never seen any that run worth a **** in my area.

 

mine is running fine. I just bought a blown90hatch conversion harness and the right ecu for my motor. but, it's still sohc in there and sohc with or without vtec still gets my vote.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">

So did you have the flat top 86-87 A1 pistons, or the 88-89 high dome pistons?

Also what tranny was on the worked A6.

Just curious.</TD></TR></TABLE>
sorry i replied so late but i couldn't see past the first post for some reason???
anyways, i had the 88-89's for pistions and the tranny was an si tranny with centerforce dual friction clutch

 

I can only vouch for the DOHC ZC. I have one. It dyno'ed at 114 Hp and 98 ft-lb (stock), consistently. It pulls pretty good.


Marc

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mar778c &raquo;</TD></TR><TR><TD CLASS="quote">I can only vouch for the DOHC ZC. I have one. It dyno'ed at 114 Hp and 98 ft-lb (stock), consistently. It pulls pretty good.


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

mine sohc zc vtec pulled 118 whp on a mustang dyno stock.... and i spanked my friends dohc zc every single time at the track. it is mainly stock".

im running obd0, with a vafcII to control vtec, with a short ram intake and a crush bent cat back....i ran a 15.8 with a shitty 2.3 60' foot, cause i was launching too high [3600rpm]....so who else has their opinions? besides, i like hearing vtec

 

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

mine sohc zc vtec pulled 118 whp on a mustang dyno stock.... and i spanked my friends dohc zc every single time at the track. it is mainly stock".

im running obd0, with a vafcII to control vtec, with a short ram intake and a crush bent cat back....i ran a 15.8 with a shitty 2.3 60' foot, cause i was launching too high [3600rpm]....so who else has their opinions? besides, i like hearing vtec </TD></TR></TABLE>

ya thats the vtec model, he cant afford to buy the zc vtec engine only the sohc zc. FYI, all Lynos (dynos) throw out diff numbers his 114 whp, can be up as high as 122 whp on your dyno

 

Search n00b!

 

i speak no ****!.... i had my 88 CRX SiZC dyno'd on a $85,000 dynojet and i got 152 hp with 107 lbs of tq......this was a all wheel drive dyno.. only 5 made.... ford has 2, place at home in TN. has one, one is owned by a ind. person at home, and some mom and pops place in ohio has the other..... i dont know what was done to the engine in japan before i got it but it runs hella good.... i raced a few months ago at a 1/8 mile track in knoxville TN (411 dragway) and took a type r 3 out of 4 runs..... 2 of 2 on a new Si.... 1 of 1 on a boosted teg...... and a new jeep grand cherokee.. (nothing to brag about!!!) but in the 1/8th i have only been beaten 1 time against the type r..... i missed 3rd gear...... actuallly the selector fork in the tranny broke..... did not find it broken for 2 months...... that tranny took a beating..... i would go with the DOHC ZC hands down to any other engine i could swap in for less than a grand.......... period........ as far as not being able to find one there..... shop around..... we can get then all day in TN..... is it worth a short drive to save shipping?....... i can put you in touch with some peps in Tn.... i live in michigan now........ lets see ... it took me 5 hours to drive to atlanta from where the engines are......... in 2 words ...... road trip IM me for details if you need too

 

https://honda-tech.com/zerothread?id=931248

As per my measurements...the A6 and the sohc ZC have the same heads, and pistons...Block is disassembled on Wed.

-Jake

 

even though the DOHC ZC is rare in your area, i'd go with it. my friend has one in his hatch, and i've done alot of wrenching on it. it has really surprised us how quick this lil car is. he also has a ZC tranny, which i would get no matter which engine you friend ends up purchasing. the only downside to that is 5th gear is a tad tall for highway driving, but that can be swaped. if you havent already, check out http://www.thezcr.com its the best place for ZC info. oh, and feel free to drop me a pm if you want. i might not be able to answer everything, but i can try.