ZC SOHC vs ZC DOHC

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moosebrew

New Member
Hi guys, thanks for loooking. I have been searching and searching and so far have decidedto go with either the SOHC or the DOHC ZC D16 JDM OBD0 for my 90 Civic DX. I decided on these two due to the ease of the swap. This will be my dd and I'm not trying to make a racer, just a dependable dd with decent mpg and the abililty to pass others.

I have a couple of questions I could not find the answers too and I'm hoping you can help. I found the Honda Engine List here in the tech section and I noticed I'm looking at around 129HP for a JDM ZC DOHC if its the 9.6:1 compression. Good improvement over the 92HP stock motor that was in my car.

Questions:
-What is the HP rating for the OBD0JDM ZC SOHC motor. I see the D16A6 has a HP rating of 108, is this the same as the JDM ZC's being sold?

-Are all the OBD0 JDM DOHC ZC's 137HP as they are being advertized?

-Anyone have any real mpg numbers for theOBD0 JDM ZC SOHC vs the JDM ZC DOHC?

It seems no one has the DOHC in stock for the time being and I'm looking at paying around 450 for a SOHC and anywhere from 650-800 for a DOHC if and when they are in. If the HP rating of a ZC SOHC isn't that much less than the DOHC I will probably just go with that due to it being cheaper and available now since my stock motor went tits-up.

Thanks for the help
Mark
 
SOHC ZC non-VTEC is advertised by Honda at 118hp (120ps) - DOHC ZC is advertiesd by Honda as 128hp (130ps) - most stock SOHC ZCs with I/H/E will dyno from 100-104whp - most stock DOHC ZCs with I/H/E will dyno from 117-120whp, which would make it closer to the 137hp that some engine importers advertise - MPG will vary depending on which transmission you use, how heavy the car is and how hard you drive it - in general the SOHC will get a little better mileage, but not a lot better - a lot of DOHC ZCs will get around 35mpg, some more, some less - having swapped many of these engines (around 40 DOHC ZCs), i would definitely go with the DOHC version - it is the quickest stock D-series engine that you can put in it
 
True that the twin bump-stick makes a hair more power but isnt the aftermarket following better for the single cam?
 
The SOHC ZC is basically a D16A6 with a hotter camshaft that has more intake-exhaust overlap than the USDM engine. If you're looking for just an engine swap and then nothing else, go with the DOHC ZC. It can be upgraded, but finding parts for it is getting harder all the time.

Upgrades for the SOHC ZC are a piece of cake- everything that will work for the D16A6 will work with the SOHC ZC. As a result, maintenance if something breaks is a lot easier and cheaper too.

My CRX had a SOHC ZC in it, and my wife's EF sedan has a SOHC ZC that I put in 2 years ago. It's still running strong, and it gets 44mpg on the highway running 70mph. We get around 30 in the city. Keep in mind that the sedan is heavier and has a shorter final drive than the hatch and CRX (except the Si), so it gets worse mileage than other EFs.
 
Thanks for the info guys. Seems that most people on hear recomend buying a motor from hmotorsonline but they have no OBD0 SOHC or DOHC right now. They said to call back around the 25th when they are expecting a shipment. If they have some DOHC's on that shipment I will probably go with that but if all they get in is the SOHC's I will probably just go that route since I'm having to drive the minivan:mad: to work right now.

Having the better hp right out of the box would be nice but it ins't a must since going with a fresh motor either SOHC or DOHC will be a great improvement over the stock one.

Thanks again
Mark
 
Wait for the OBD0 SOHC. I bought the OBD1 because I had to have the car running, but buying the OBD0 hardware I needed to get it to work really raised the cost a good bit.

The DOHC does have more power than the SOHC, but just a little bit of modding will get your SOHC ZC up past the DOHC's power levels without spending too much money.
 
What kind of cheap mods would do that on a SOHC? Would those mods completely kill the mpg also?

Thanks
Mark
 
The basic stuff that you bolt on- intake, header and exhaust- increase power by increasing efficiency. They will help your power output and help your economy a bit too. Start adding on stuff that you have to richen up your fuel maps for and then you start to eat it on gas costs.
 
Great information, you've got me leaning towards the SOHC now. For an average of $200 less than the DOHC and stock only around 10-15hp less I could add headers and a cold air intake down the road even and be ahead.

Now only if hmotorsonline got some in! Would you risk buying one from ebay if they never get them in?

Mark
 
I would wait for hmotors to get one they go over all their motors before selling them, with ebay you really dont know if your getting a good motor. Just wait theyll get one in.
 
If I end up going with the DOHC would the extra weight be an issue? Do you recomend upgrading the front shocks/struts to stiffer ones? Keeping in mind this is strickly a daily commuter.
 
If I end up going with the DOHC would the extra weight be an issue? Do you recomend upgrading the front shocks/struts to stiffer ones? Keeping in mind this is strickly a daily commuter.
Its not enough extra weight to make a noticeable difference.
the DOHC ZC weighs 13 pounds more than the SOHC
 
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Thanks, for some reason I thought I read somewhere that it was something like 200lb's more. I'm planning on replacing the axles and struts while I'm dropping the engine in. Do the springs need to be replaced as well or just the struts?

I'm hoping to get my engine ordered tomorrow and have it in and running by the 4th!

Mark
 
Honestly, if your not having trouble with you struts, why replace them. Is the car bouncey, do the struts squeek or knock?
 
I think I put some in it like 6-7 years ago but now when going over train tracks or bumps it just seems rough and like they are not absorbing much if any.
 
Well went to order the motor today but they did not get any of the OBDO's in, those are expected on July 9th. So a couple more weeks of waiting :(
 
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