this may be the wrong section but i have an 89 crx hf and i was thinkin of doing a dohc ZC swap and i thought of a few things 2 figure out... since mine is an hf do i need 2 change out the hubs? (hf has like 22 or 23 teeth and si has 26, if im not mistaken) and do i need an si wiring harness or can i use my hf 1? and what is the best ecu 4 the swap? idk much about ecus so more information the better... thanks alot guys

 

i could be wrong, but i think since it is an hf, you can use your wiring harness, hubs all that good stuff. as far as ecu, i couldnt tell you. i am asuming a 88-91 si computer would be the best.

 

thanks... iv heard many diff things.. i got kinda confused.. iv heard use 1 from a 90-91 ZC and 1 from a 86-89 teg and some others.. gets rather confusing

 

i don't know about the ecu, but i do know that you have to swap the hf hubs with dx/si ones.

 

and i was wondering if 700$ is a good price 4 a ZC swap... it include the following:
motor, cable 5spd tranny, intake mani/ exhaust mani, dizzy, fuel rail, injectors, alternator, starter, and intermediate shaft... if ne1 knows where 2 get a better deal or nething lmk thanks

 

you will need to get dx/si hubs, you can use your wiring harness, you can use a pm6 out of a crx si, or u can use a pg7 out of a 88-89 integra, or you can use a pm7 which is the zc ecu here is a good website with a lot of info http://thenew.gamesbbs.com/~dmoore/zc.htm

 

$700 for a complete swap isnt too bad, hmotorsonline sells the engine alone for 525 bucks, so id go for it

 

i found some hubs 4 a b series... will those work?

 

is there ne diff between usdm ZCs abd jdm ZCs? like wirin wise or nething? cause the swap i found is jdm

 

No such thing (technically, before someone jumps down my throat) as a USDM DOHC ZC. The only "DOHC ZC" that made it to the states that I'm aware of came in the 86-89 Integra's and was called the D16A1.

However, before you get any ideas, the mounting points on this engine are not compatible with the second gen Civic/CRXs (88-91). It is most often swapped into the first gen CRX.

And the JDM ZC should go into your HF fine, with new hubs, as was said previously.

 

so the ZC ur talkin about from the 86-89 wont fit? kinda lost me there... i mean i found the swap on japanese engine import inc.. so just get new hubs adn the swap and it should go in easy? no diff motor mounts or nething? i was reading on a site that they had 2 switch the exhaust mani or something like that cause the ZC uses a 4-2 design and the SI uses a 4-1 or something...

 

if i change out the hubs will i have 2 change the lower part of the strut assebly? the part connected 2 the balljoints?

 

if your gonna use the stock exhaust manifold you have to make the holes on the manifold bigger because they wont line up perfectl.

 

1st gen DOHC ZC - brown valve cover - came in 86-87 JDM Integra - will bolt directly into 1st gen CRX Si and 3rd gen Civic Si - will not bolt directly into 2nd gen CRX or 4th gen Civic.
2nd gen DOHC ZC - black valve cover - came in 88-89 JDM Integra - will bolt directly into 1st gen CRX and 3rd gen Civic, same as brown valve cover, however, it uses electronic advance distributor like 88-89 USDM Integra D16A1 - 1st gen CRX Si and 3rd gen Civic Si have vacuum advance distributor, so, to use it on 1g CRX or 3g Civic, you will have to do a lot of wiring changes.
3rd gen DOHC ZC - black valve cover - came in 88-91 JDM CRX Si and Civic Si - bolts directly into 2nd gen CRX and 4th gen Civic.
4th gen DOHC ZC - black valve cover - came in several different models of JDM cars 92 & up - is OBD1 - has Cylinder Position Sensor inside the distributor and will bolt directly into 92-00 Civics
SOHC ZC - basically the same as D16A6 (little more horsepower) - will bolt directly into 2nd gen CRX and 4th gen Civic.
SOHC VTEC ZC - basically the same as D16Z6 - OBD1 - will bolt directly into 92-00 Civic

DOHC ZC Specs.

1.6L (1590 cc) DOHC
130-135 hp @ 6800 rpm
Bore 75.0
Stroke 90.0
C.R. 9.5:1 I can find no evidence of it being any higher than this.
91 octane. Some have reported no problems with 87, but the specified gas is 95 and/or 96 RON, which is equal to 91-92 'pump octane' available in the US.

The ZC comes with a black valve cover with the cover bolts on the sides
The Honda symbol is on the exhaust side of the valve cover
The ZC comes with a 4-2-1 header style exhaust manifold
The ZC comes with a small oil to water oil cooler on the back of the block
The ZC has the same mounting points as the standard 88-91 CRX/CIVIC
The ZC will bolt right in to the 88-91 CRX/CIVIC no fabricating or welding is needed

The swap can use your existing wiring harness if you have an SI or HF, if you have a DX or STD then minor modification is necessary. There is info on this procedure here

The engine only adds about twenty-five pounds to the front of the car, so your steering and suspension should be the same. Your ZC didnt come witht he header. The scoop on the headers, is that while the bolt pattern for the Civic SOHC engines and the ZC engines are identical, the port pattern is not. The ZC engine has the ports shifted almost 3 mm (appx 1/8"). In real terms, this means that when you use the SOHC header, the ports do not align properly. The exiting exhaust gases literally run into one edge of the misaligned header flange. You can see this by holding the steel exhaust gasket from the ZC engine up to the DC header.

The easiest and best solution is to use the ZC gasket as a template and mark the misalignment. Using an air grinder, with a small stone "port" the header to match the ZC port configuration. While you're at it clean up the entry point of the header a little so that the whole port on the header is slightly larger than the ZC port. It is an old, but proven trick that the larger header port decreases the chance of exhaust gas reversing flow and re-entering the still open exhaust valves. It is better to have the port larger than to have them matched identical. Do not under any circumstances grind the port on the head to match the header though. This gives poor results."

Transmission Options

Spline count refears to all d series L3 transmissions. First spline count on the input shaft to determain year. 21 splines is 88, you can use an 88 or 89 flywheel(d-series) but have to use a 88 specific clutch. Confused yet? If you have 20 spline count you have 2 options, 1. use and 89 clutch with an 88 or 89 flywheel 2. use a 90 and up clutch with a 90 and up flywheel. I recomend #2 because of the aftermarket trans,flywheel and clutch options are higher.

You may have gotten a ZC trans. with your ZC so heres were to start if thats the case. The ZC trans. requires you to use ZC or 90-91 Integra axles, and a ZC intermediate shaft. Because these axles are equal length, many users report a reduction in torque steer.

Also, when using the ZC transmission in CRX HF or Civic STD, you will need to swap knuckles/hubs for ones from Si or DX.

Now some are lucky and get a ZC with a L.S.D then pass this section. You can get a L.S.D for your ZC trans. is the same as with any D series trans. You just have to be year specific when ordering since the 88 is a different size then the 89-91.

Another option is a hyrbid zc/si trans.by taking the Si final drive and put it in the ZC trans. or you can do it the other way around, ZC 1-5 in a Si transmission case. Either way, expect 80mph to turn 4300 rpms.

You can bolt a DX,HF or SI trans. and they will bolt up directly. Again just do the spline count trick to find your year and buy your clutch off of that. The Si trans. is the best choice available. The DX transmission will sacrifice performance for better fuel mileage and lower freeway rpms.

What to Expect

Unless you picked up your ZC your ZC just arrived. Now try not to hump it and carefully go over teh entire engine. Heres what to look for as far as what you need to replace.
Check all the seals and replace all you can afford too it is manditory to replace them if there are noticable leaks around them. cam seals, rear and crank seal are from an 89 integra.
TPS sensor is located on the rear of the throttle body. You can get one from a dealer or a junkyard, use one from an 88-91 si or a d16a1 acura integra. If you have to you can replace the entire tb but this could get pricey.
Distributor most come with it but some dont. For obd0 engines you can replace the dist. with a 89 d16a1 integra. Either way you go with a new or stick with the old I recomend only using Honda OEM cap and rotor button. I use one from a teg. some use an si.

Radiator hoses need to be an 84 accord for the top and a 88-91 crx bottom. You will need to trim a little of the top hose or you can use the 88-89 Integra top hose which fits without any trimming.

Replace your timing belt now or pay the price later. use one from an 88 prelude si. Timing is kind of tricky so follow the manual. Here is an aritle from these forums with cam gear pics to help out.
Thermostat if you need to replace it is one from an 88-91 crx.
Oil filter can be 89 teg or 88-91 crx.
for part numbers refer to this list
ECU options- 1) PM7 (JDM ECU) - This was the original ECU for the imported DOHC ZC. It has a speed limiter set at 112 MPH, though. How often do you hit those types of speeds, though.
2) PG7 ('89 Integra) - This is a great ECU for this engine. Some will say that it tends to make the engine run a little bit rich. Make sure you get the ECU from a 5 speed.
3) PM6 ('90-91 CRX Si) - This era of CRX ECUs have more aggressive fuel and timing curves than that of the previous years. These ECUs should be cheap and easy to find


FAQ
Engine code question- ZC is on the badge of th JDM ZC the serial # below if it starts with 2 means its from a Civic/CRX if a 5 it comes from @nd gen integra.
Mounting- You can swap the ZC into a any 88-91 Civic body trim. No mounts are neccesary and the shift linkage will connect right up.
Realiabilty- First these are used engines and despite the 30k# everyone seems to quote its still a used engine. have a compression check done before you buy (expect 160 psi or better in each cylinder) and better yet is a leakdown test. The other issue to look at is YOU should take the time to not only install it right but also replace all the parts that generally can easily be replaced.
Rebuilding prior to swapping- This is your choice, rebuilding will be more reliable and add some life to the engine. Stock internals are generally fine(leakdown test will determain this) but there are alternatives. Of you plan on going FI above 10 psi then rebuild the bottom end, stock internals are good to roughly 200 hp. This is not 100% because the weakest link can cause an engine to fail at stock hp.
ZC vs B-series- by all means do what you want. The B-series has much greater HP but with that comes a greater cost and complexity with the B swaps running well over $2000 without the installation. Choice is yours though and if your not mechanically inclined add swap cost to either engine.

 

ok i f i change the hubs can i use my stock calipers and whatnot or do i need 2 switch those out.. thanks 4 the info nblkid... that helped alot..