Tools
Socket Wrench + Sockets
Air Tools/Impact Wrench (I didn't use any air tools for my swap but it would make doing it much easier)
Engine Hoist (ZC weighs about 220lbs so the hoist has to be that strong at least)

Parts
Complete ZC engine (with either a ZC or Si transmission recommended)
MPFI Parts (if you have a STD/DX)
Axles:
·  ZC Tranny; 90-93 Acura Integra Axles + ZC Intermediate Shaft (you can use a 88-89 Integra Intermediate Shaft if you cut the top bolt hole off).
·  Any 88-91 Civic/CRX Tranny in Si or DX (or any 26 hub spline car); 88-91 DX/SI 26 outerspline axles.
·  Any 88-91 Civic/CRX Tranny in HF or STD (23 hub spline cars); 88-91 STD/HF 23 outerspline axles.
Si throttle cable (if you have a STD or DX, you can reroute the stock cable but I recommend just getting the Si one)


The Honda UK website offers these very helpful online manuals in PDF format, Online CRX Manual  and Online Concerto Manual.  Both include alot of info on the ZC (D16A8/A9).

What is a ZC?
The ZC was a group of Honda engines for the Japanese market. There were several kinds of ZC. There is the brown top ZC(similar to D16A1), which only bolts into the 84-87 Civic/CRX, and not into the 88-91 Civic/CRX, so we won't worry about that. But just giving fair warning if anyone wants to give you a really good deal on a brown top ZC swap for your 88-91 ;). Then there are the black top ZCs. These include the DOHC ZC, the SOHC ZC (similar to a D16A6), and the SOHC VTEC ZC (similar to a D16Z6).

What ISN'T a ZC?
There is a common misconception that the DOHC ZC came in 88-89 Integras. THE ZC IS NOT AN INTEGRA ENGINE. The DOHC ZC is SIMILAR to the D16A1 Integra engine but it is by no means the same. D16A1 engines WILL NOT bolt into the 88-91 Civic/CRX chassis, it will howeever bolt into a 84-87 Civic/CRX if you have one of those. Also the DOHC ZC does not have VTEC. There was a SOHC ZC with VTEC but the DOHC never had VTEC. If you want DOHC + VTEC get a B16A.

What about D16A8 and D16A9?
These engines are essentially ZCs from the European market.  They come from European Civic, CRX, and Concerto from around 88-91 (possibly even later in Concertos), as well as Rover 216/416 GTI (rebadged Concerto) from around 89-96-ish.  They are identical in almost every way to the Japanese market ZC, same horsepower, same torque.  The engines from Honda cars look identical to the ZC, while the engines installed in Rovers have a distinctive striped valve cover (without any Honda branding), a white timing belt cover, and may come standard with a 4-1 or 4-2-1 exhaust manifold.  As far as i can tell, they're probably ~122-130hp, atleast in the stock Rover setup. The difference between 122 and 130 seems to be down to the different header designs used in different models and in different years (and possibly different markets). I suppose the cat. and ECU also play a part in the difference. For example, this link shows 2 different stock exhaust setups for the 216 GTi. A 4-1, cat. version producing 122hp, and a 4-2-1, no cat. version producing 130hp. Another difference worth mentioning, the D16A9 was designed to be run without a catalytic converter.  From what I understand of Honda’s specs for the engine, it has lower compression (9.1:1)than the ZC (9.6:1)and A8 (9.5:1), yet produces the same hp because it lacks a cat. It only makes sense that running this engine with a cat will not produce the same power.   One potential bonus to finding an A8/A9 from a Rover is that it could be up to 8 years newer than a JDM ZC or EDM Honda A8/A9. 

Honda ZC	D16A8/A9
	Honda	Rover

Can I do this swap on an automatic?
Yes.  You will need an automatic ECU and the MPFI conversion (if applicable) is slightly different.  Other than that, it bolts right up and works fine.

Why do a ZC swap over a B-series?
There are two reasons to do a ZC swap, ease of installation and cost. Basically it bolts right in and they are dirt cheap. I got my ZC for $450 from a local seller and it came with the transmission, axles, everything basically. Most people get them from importers for about $500 + shipping (which is the downside since it costs a lot to ship an engine). The bonus of getting them local and slightly used (again, since they are already used to begin with from Japan) is that you don't pay shipping and all the vital things like timing belt and water pump and all that have already been replaced and won't have to be replaced again for a while so there is less downtime before installation. Also the ZC bolts right in using your stock mounts and shift linkage, the same is not true for the B-series.

ZC vs B-series!
Cheaper of course will never buy you more power (unless you drive a domestic)! The DOHC ZC makes 130hp without VTEC. A B16A makes 160hp using VTEC. A good driver with a ZC could beat a B16A powered car but hes got less of a chance of doing that. However look at what you get for the money...

Prepping the engine for installation
You don't want to go straight dropping in your ZC as soon as it comes. Its seals and parts are old and should be replaced if you want any reliability. Here are parts commonly replaced before installation and which part correctly fits on the ZC...

Use a Chiltons, Haynes, or preferably a Helms manual on how to install/replace all these parts. 

Getting the old engine out...
Getting the stock engine out is much harder than putting the new one in. You will find rusted bolts and various siezed parts which will make it a bitch to get out. Heres a quick run down of things you need to take off to get your old engine out...
-Various A/C components (if you have it): see the A/C Removal How-To for more instructions.
-Drain the fluids: undo the bolt on the bottom passenger side of the radiator to drain the coolant, undo the oil pan bolt to drain the oil from the engine, undo the tranny plug to let the tranny fluid out of the engine.
-Radiator and hoses (frees up room and prevents damage to radiator): Remove clamps on hoses, then remove the fans by taking off their bolts and pulling them upward, then take off the radiator mounts which have 2 bolts each, then pull radiator outward and up.
-Axles, see the Axle Removal How-To for more instructions.
-Header: 9 bolts hold it to the head, 3 bolts hold the 2 pieces together, 2 bolts hold it to a bracket under the car, and 2 bolts hold it to the Cat Converter. Expect the worst rusted bolts to be found here.
-All vacuum lines: Just pull them hard, remove any clamps if they have them.
-Detach engine harness plugs from the chassis connections: Press in tabs and pull outward.
-Shift linkage from transmission: the pin is called the "Bitch Pin" for a reason, supposedly an 8mm punch gets it out, I heard an air chisel works wonders. I had to lower the stock tranny out the bottom and then use a new linkage in which I placed an M8 bolt with thread locker instead of a pin to hold the linkage.
-Clutch Cable: Undo the nut on the cable until it is loose then slip it out of the bracket.
-Disconnect the fuel hose from the fuel rail: It should be held on with a large "nut" type thing, use locking pliars to make sure it doesn't leak fuel out of it.
-Speedometer cable from transmission: pull off the boot, pop out the clip, pull upward.
-Engine mount: it helps if you do front, back, passenger side, then driver side in that order) stick a small jack under the engine to support it when the mounts are off. All of the bolts are pretty obvious, the passenger side mount has 1 nut that must be accessed from underneath the car.
-Hood: 2 bolts on each side of the hinge. I didn't have to have to hood off to take the engine out, but it helped when putting it in.
-I think that is everything, anything left over should be pretty obviously holding the engine in.
*For pictures of these instructions go to the Helm's Engine Removal and Installation

Out with the old, In with the new...
Find a spot on your engine to attach the chain to. Make sure to use a strong bolt, I used some of the mount bolts to thread into various spots onto the engine, luckily the threads on these engines are pretty much the same as long as they are the same sized hole. Once the chain is attached securely lift the hoist so the chain is tight, then undo any last engine mounts, once the engine is free jack it up high enough to clear the hood support and then roll the lift backward and lower the old engine to the ground...

D15 being taken out...

Now go climb inside your engine bay and check out all the cool things you could never see before...

If your car is DPFI now is a very good time to do the engine harness wiring for your MPFI swap, check out the MPFI Wiring How-To and this Acura PG7 ECU pin-out (Printable).

Now attach the ZC to the hoist chains and lift it into the engine bay, wait until the engine is in position and then try and install the engine mounts. Attach the 2 side ones first, then the front, then the back.

Installing the ZC
Remember all those things you took out of the car before? Now try and remember how they go back in. Good luck. Don't forget to fill the car up with fluids again. For the tranny fluid make sure all the old fluid is drained out by unscrewing the lowest drain bolt, then reinstall the bolt, undo the bolt in the middle drain bolt, fluid will pour out of this when the tranny is full. With the starter off of the tranny fill bolt under that and use that hole to fill the tranny, stop when fluid pours out of that middle drain bolt hole. Then reinstall all bolts and the starter. For the coolant fill up the radiator until it is full, you will have to wait until the engine works to bleed the system but all you have to do is run the car for 10 minutes until there is no more bubbles in the coolant. For fuel attach the fuel line to the ZC fuel rail. On my DX I had to get an Si fuel-filter-to-fuel-rail hose and "nut" because my DX hose was not the correct length and attached to the rail differently.

Exhaust Manifold
There are several options here. 
-If your engine came with a complete exhaust manifold (header and downpipe), you can use it, of course.  It’s a pretty good design, but heavier than aftermarket. 
-If your engine came with a stock 4-2 header, you can get a 92-95 Civic EX downpipe.  It will mate up, but may hang alittle low. 
-If your swap didn’t include a header, you can use your stock D15/D16 header, but it will need to be ported to match the ZC exhaust ports.  Use an 88 Integra exhaust gasket as a template.  However, I would recommend upgrading to a proper 4-2-1 style setup, whether it be aftermarket, or pieced together from a stock ZC header and 94-95 Civic EX downpipe.
-If you want to upgrade, you can use an aftermarket header for an 88 Integra. 

If you happen to get an oddball D16A8/A9 from a Rover, some came standard with a 4-1 header like the stock 88-91 Civic (except properly port-matched), so you can just bolt it up to your stock downpipe.  Again, I would recommend upgrading to a 4-2-1 style setup.

Vacuum Hoses
You will see that the Vacuum Hoses for the STD/DX and possibly Si aren't exactly in the same places. But here is how they should be hooked up.

Sensors on the firewall...

The 2 vacuum hoses from the MAP Sensor and Purge Solenoid Valve (PSV) are to be joined together with a "Y" Connector. You should not leave the hose from the PSV vented to the atmosphere because it's job is to open up to release the trapped hydrocarbons inside the charcoal canister into the engine's intake manifold so they can be burned up. If you do not have this system hooked up properly, the hydrocarbons will be released right into the atmosphere which is horrible for the environment. So do your small part and make sure you hook it up correctly.

Which plugs go where?

Intake Air Temp Sensor (TA Sensor): Green/White, Red/Yellow

Electronic Air Control Valve (EACV): Blue/Yellow, Black/Yellow

Left Over Unused Plug: Orange, Black/Yellow

*You will have one white plug left over, it should hang from about the back-middle of the engine, it is a left over and there is nothing that it goes to.

Notes
Have patience.