Technical Specs  

C.R. 9.5:1 for the Japanese model

C.R. 9.3:1 for the European model

7200 rpm redline One of the major reasons that ZC's blow up
is because many people confuse the Integra computers 7800rpm
fuel cut off as a red line. 

Engine Identification   

ZC ~ Japanese model - comes in several varieties. Injected, carbed, sohc, dohc, brown valve cover, obd0 and obd1.

For the 88-91 CRX/Covoc you want a ZC with a black valve cover with the cover bolts on the sides and the Honda symbol on the exhaust side of the valve cover.  They come with a 4-2-1 style exhaust header and a small oil to water oil cooler on the back of the block.  The engine mounts are the same as the 88-91 Civic/CRX.

Note - be sure it has a black valve cover with the cover bolts on the front and back edges of the valve cover and that it is a DOHC design.   There is an older ZC with a brown valve cover that you don't want!  Also watch out for the Integra motors which look identicle to the ZC except for the valve cover bolts are not on the edges of the cover, this motor will not bolt into the car.

Swap  Info

• The ZC bolts right in to the 88-91 Civic/CRX with  no fabricating or welding. If your car is an Si or HF the wiring harness will hook right up with just the change of 2 wires on the distributor.  If it is a DX then some more significant wiring changes are necessary since the DX motor does not have MPFI (Multi Point Fuel Injection)

• You can use the ECU from either the U.S. CRX Si, 88-89 Integra 5 speed, or the Japanese CRX Si which is what the ZC came out of anyway.  The best choice would be the Integra one since it has more aggressive fuel and timing maps as well as a higher redline than our CRX Si ECU and its readily available, .  The Japanese Si ECU is probally just as good but they are very hard to get and have a speed governor that is set at too low for most peoples taste.

• The motor bolts right up to the stock motor mounts and to the tranny.   While the HF tranny does bolt onto the ZC you will definatly want to use an Si tranny because of the much better gearing, you may even want to consider this if you have a DX. 

• Replace the clutch.  As long as everything is apart it doesn't require any extra work to replace it.  A performance clutch is reccommended because of the ZC's greater output.

• The motor only weighs about 25 pounds more than the regular CRX one so handling is not affected.

Maintnance

• Spark plugs ~ 88-91 CRX or 89 Integra
• Distributor ~ 88-89 Integra
• Timing belt ~ 88 Prelude Si 2.0 This is the right one despite what some other ZC sites say
• Thottle body + TPS ~ 88-91 CRX Si
• Cap and rotor ~ 88-91 CRX or 88-89 Integra
• Head gasket ~ 89 Integra
• Intake gasket ~ 89 Integra
• Exhaust gasket ~ 89 Integra
• Water pump ~ 89-91 CRX
• Oil pan gasket ~ 88-91 CRX or 89 Integra
• Oil filter ~ 89 Integra
• Spark plug wires ~ 89 Integra
• Header ~ the 88-91 CRX header will fit but requires some porting to work properly since the exhaust ports on the ZC are shifted slightly to the side
• Thermostat ~ 88-91 CRX, actually I think most Honda's use the same one
• Rod and Main bearings - 88-89 Integra, I believe the bearings are the same as CRX ones though.
• Pistons ~ 88-89 Integra are exact matches for ZC pistons
• Gaskets ~ the top half of the motor uses a 89 Integra set.  I forget what the bottom half is, i'll add it when
  I dig up the info.

Misc. notes

• Stock ZC rods are said to survive up to about 200hp / 8000rpm's
• Shaving the head .8mm will give a cr of about 10:1 while a shave of 1.4mm gives a ratio of 10.6:1
• The upper timing belt cover on the ZC may rub on the bottom of the hood.  Most people solve this problem by just leaving it off.  Another solution is to put small 1/8" washers in between the two parts of the drivers side motor mount, this lowers that side of the motor just enough to clear the hood.
•  

Performance

• Stock ZC powered CRX's vary alot.
• ZC with header, exhaust, throttle body, cold air intake and an integra ecu have run as fast as the mid 14's to the upper 15's.  I guess it all depends on driving skill, condition of the motor, and the persons exaggeration.

I Need One

• Price $350 - $600
• Nippon (Cali)1-562-272-4050, Ask for Felipe, he's the ZC guy
• John's Foreign Engines (Wash State) 1-360-571-8505
• PFI in (Colorado) 1-888-296-3463
• Prices and companies are always changing so check out the many honda related message boards for up to date info on who has the best motors and prices.
• Everyplace that sells the ZC claims that they have about 30k miles on them, but keep in mind that there is no actual way to know this for sure.  Some of the better sellers will perform a compression test and provide you with the results.