hello my fellow crx'ers
I would like to swap a d16zc on my 1988 crx but I'm pretty new at motor swaps.

I think I would like to do this swap myself since its seems very similar to the motor I have now (d16a6) but need some help if anyone has a step by step procedure write up that I can follow. going to be buying from hmotorsonline.

another question is will I be able to pass smog with this? its like a replacement motor right but? (i know it just has bigger cams)

Thanks.

 

D16Z6/D16Y8 engine swap to 88-91 4G/2G civic/crx
text by Mechanic_b
Last updated: April 10, 2002
beware of any knock offs, bootleg or similar sohc vtec tech info out on the web that uses my tech info
Sohc vtec engine bay
1.6L D16Z6 92-95 EX/Si (5G) or 96-00 D16Y8 EX (6G) is one of the easiest bolt-on engine swap for your tired 2g crx/ 4g civic 1.5L or 1.6L. With the popularity of Dohc Vtec swaps into 5g civics, there's a lot of sohc vtec motors available out there just waiting for you. It's cheaper than Dohc swaps, availability of the engine, lot's of bolt-on parts and you could even use most of your old go fast goodies from your stock non-vtec engine. Basically you could either just use the long block of a sohc vtec (less modification) or use the whole 5g parts (more complicated). Me ,Mechanic_b and Lagboy chose the easiest and most convenient but effective route which is just using the vtec block, external vtec controller and use the rest of our existing 4g parts. A lot of potential hybrid swappers think that you'll loose performance and reliability of the engine just using the block and not use the rest of 5g parts like ecu, distributor, intake manifold, harness etc. But results speak for itself , with an e.t. of 14.1 @ 94 "all motor" e.t. and 13.1 @ 104 mph e.t. with Nos 60 shot single fogger is much more convincing than saying you have more top end power or I could feel the low end torque much better than my old non- vtec engine, right. Most of the cars we've worked on with this set-up brought home some high and low 14's and even high 13's All Motor, high 12's with single fogger Nos 60 shot. These timeslips were done running on slick tires, of course and with just basic bolt-on ( I/H/E ), no P&P head and non-built stock block. Sorry no Dyno results here, my dyno is the 1320ft(1/4 mile). Now Smog Referee Certified even with the use of 4g intake manifold, throttle body, distributor, harness and ecu.

Parts list
Tools and stuffs needed for the swap
Recommended parts to be changed
Preparing your engine
Preparing your tranny
Preparing your distributor
Preparing your vtec controller
Tech tips
So here's the list of the parts that you need and options if you're gonna use just the VTEC long block for Dx,Hf or Si model:
1) 92-95 D16Z6 (9.2:1)or 96-00 D16Y8 sohc vtec block (bigger intake/exhaust ports and higher compression (9.6:1)as shown below second and third photo compared to a D16A6 non-vtec block. Notice the combustion chamber similar to 94-up Integra GSR. Beware, 96-00 sohc block are prone to main/rod bearings failure. Most of the 96-00 sohc engine I've worked on had the the same problem. But 96-00 D16Y8 heads are a good VTEC head upgrade to 92-95 D16Z6 short block. It will bump extra compression about .5:1 with the D16Y8 head on D16Z6 short block.
2) 4g Si/EX intake manifold and throttle body IF 1)you already have aftermarket throttle body and p&p intake manifold, 2) you have an Si model to begin with, or 3)the sohc vtec block didn't come with intake manifold or throttle body. Which ever convenient for you.
ADDED Due to tons of email concerning dx manifold being used instead of a Multiport injection. The dx manifold tends to have problem to conpensate for the extra fuel needed when the vtec activates. Si/Ex Multiport injection manifold, harness ,distributor ,ecu and Throttle body are much more desirable.
3) Or 5g intake manifold & throttle body IF came with the long block.
4) 4g left/driver side engine mounting bracket and engine mount
5) 4g stock Si/Ex/Dx/hf tranny and mounts note: again preferably 89-91 Si model for performance reasons. will explain later.... For tranny mounts upgrade to get rid of engine/tranny flexing toward the fire wall. Get 88-91 civic/crx Energy Suspension mounts insert to stiffen up the mounts.
6) 4g stock axles (DX and Si models are the same except for 4 spd and HF model)
7) 4g Hf,EX or Si distributor for 88-91 PM6 civic/crx ecu or 88-89 PG7 integra ecu ( 92-95 ex/si OBD1 distributor won't work with non OBD PM6 or PG7 ecu, it only works w/ 92-95 ex/si OBD1 P28 ecu and vice versa )
8) 5g or 6g Ex/Si/Vx ignition wires note: 4g ignition wires will work too with slight mods
9) 4g Si/Ex engine harness for Si/EX intake manifold/ecu/distributor or 4g Dx engine harness if you're gonna use 4g Dx manifold/ecu/distributor. If you have DX model and want to use 4g/5g manifold, you need to convert your Dual Port dx harness to Mulitport injection. For DX to Si wire harness conversion click here.
10) 4g Si injectors & fuel rail for 4g harness & 4g intake manifold, 5g EX/Si injectors & fuel rail for 5g manifold. note: 5g injectors won't plug in to 4g harness but you could use it by swapping the 4g injector connectors w/ 5g injector connectors with no problem.
11) 5g or 6g fuel pressure regulator
12) Homemade external vtec controller and 30 amp automotive relay * more info below*
13) 4g or 5g alternator belt depending on what year alternator you'll use. 4g has 3 rib belt while 5g has 4 rib belt.
14) 88-91 civic/crx PM6 1.6L Si ecu (7,500 rev limit)or 88-89 integra PG7 1.6L LS ecu (7,800 rev limit and the engine runs rich A/F ratio if you use this, good for turbo & Nos)
15) 4g stock clutch kit and flywheel or better , same year as your tranny * more clutch upgrade info below
16) And 4g coolant hoses and heater hoses
d16a6_port.jpg88-91 civic/crx si intake port
d16y8_port.jpg96-00 civic ex D16Y8 intake port
d16y8_combustion.jpg96-00 civic ex D16Y8 combustion chamber

Tools and stuffs needed for the swap:
1) Honda factory manual for torque specs and wiring diagram
2) breaker bar and flywheel stopper or just air impact to take off the crank pulley
3) torque wrench
4) lot's of metric wrenches and sockets
5) butt connectors or electric tape
6) turn signal bulb and holder with 2 wires ( to check the vtec activation)
7) Dremil tool or air grinder with metal blade/grinding stone for modifiying the distributor
I recommend to change the following while the engine's out & to avoid some head ache later on:
1) 5g/6g timing belt
2) 5g/6g water pump
3) 5g/6g head gasket (clean the pistons and combustion chamber while 'ur at it )
4) 4g/5g/6g intake manifold gasket depending on what manifold you're gonna use
PREPARING YOUR ENGINE :
Assuming that you already have the engine pulled out of your car, your vtec block is already cleaned up. Install the new intake manifold gasket and then transfer the intake manifold and then torque the nuts at 17 ft. lbs.

Transfer the Si or converted Dx to Si harness to the vtec block. On 96-00 block , ignore the (CFK) crank fluctuation sensor located inside the timing belt cover and the knock sensor at the back of the block on 96-00 civic Ex (D16Y8 block). Tip: Don't forget to bolt the ground wire of the engine harness to the thermostat housing or else your engine will not start.

Replace the 5g left/driver side engine mounting bracket and rubber mount with the one from the 4g block. Trim the timing belt cover on the front side of the engine underneath the transferred 4g bracket to clear the timing belt cover to the mounting bracket. In order to do this you have to remove the crankshaft pulley and then torque back the crank pulley bolt to 134 ft. lbs.

5g block have the radiator fan switch at the thermostat housing compared to the 4g which is at the back of the block . You could either just extend the two wires blk and yel/green and then connect it using the 5g connector for the fan switch at the thermostat housing or on" 92 block only", there's a hole plugged up by a bolt on the same spot where the 4g switch is located. Just transfer the 4g switch to the 5g block but be careful not to break the two prong connectors and put high temp sealant before installing it.

Replace the 4g fuel pressure regulator ( rated at 35-41 psi ) with 5g pressure regulator ( rated at 41-47 psi ). Don't forget to do this upgrade or else you won't have the extra fuel to compensate for the extra air once the vtec activates. This will bolt up to the 4g fuel rail plus with the help of an adjustable clamps 'coz 4g fuel return line is bigger than 5g return line.

PREPARING YOUR TRANNY AND CLUTCH:
Si and DX has the same gear ratio from 1st gear to 5th gear except for Hf model which is designed for fuel economy. And one of the significant differences between models are the final drive gear ratio. Si has 4.250 best mated for higher revving powered engine and better acceleration, cruising speed of 3,400 rpm at 70 mph. Dx model has 3.888 , little better gas mileage compared to Si but will slightly hurt your acceleration, 2,500 rpm at 70 mph. Hf has 2.954 (49 st) 3.250 (california) , has the best gas mileage but I don't think you want to swap to 5g vtec and put Hf tranny just for the gas mileage.Click here for tranny gear ratio comparison.

If you have an 88 model or tranny, you need to use the same year clutch disc, pressure plate and flywheel to either stock from the Honda dealer around $180 for the clutch kit ( or Clutch masters,ACT, etc) and 'bout $25-30 to resurface the flywheel. All and only 88 model tranny has different # of teeth on the spline (21) compared to 89-00 (20).

If you have an 89-91 tranny , you could upgrade it even if with just a stock 92-00 Ex/Si clutch disc, pressure plate and flywheel. If you use the 92-00 Ex/Si clutch upgrade , you have to use the Ex/Si 92-00 flywheel . This is a good clutch upgrade if you're on the budget and not only it's larger in diameter which means more friction material, better heat dissipation and stiffer springs in the hubs to handle torturous aggressive launches and shifting. It did'nt show any signs of slippage at the time when I was using the set up especially when I was "squeezing" considering I was pulling low 13's all day. Tip: while you're at it, change your throw out bearing because eventually it will cause you some problems if you did not replace it.

PREPARING YOUR DISTRIBUTOR:
By using a 4g Si/Hf (they're the same), you need to modify the mounting holes on top and bottom front of the distributor. Ignore the third hole 'coz you only need two bolts to hold the distributor from not leaking any oil and to align the distribu tor to stock ignition timing as shown on the pix.
On 96-on block , the 4g distributor will just bolt right up without any modification .
PREPARING THE VTEC CONROLLER:
There's lots of ways to activate the vtec. You could use a tachometer with shift light from Autometer combined with a 30 amp relay($125) Msd rpm switch ( $55) with Rpm module or module selector combined with a 30 amp relay($59) , Field SFC vtec controller ($250) or just plain ol' toggle switch ($2) but might fry up the vtec solenoid.
You don't nead to hook up the oil pressure switch for the vtec by the vtec solenoid if you're using the 4g ecu.
MSD RPM switch
Field SFC vtec controller
new! Apex-I V-AFC vtec controller
TECH TIPS
TIPS: Now after you've dropped in the engine like just dropping in 4g engine. You'll notice that the driver side mount is a lil' off and tilted to the radiator side of the engine bay. Don't be alarmed 'coz it's normal for this swap. The mounting holes for the bracket is not perfectly in favor to 4g bracket eventhough it bolts right up. Install the 4g axle and torque the spindle nut to 134 ft. lbs. Double check all fluids (oil, tranny oil, coolant ) check ignition timing, ground wires on the tranny and valve cover and engine harness main ground(-) bolted to the thermostat housing.

To determine if the vtec controller works, you can either use two wire auto light buld holder with auto light bulb( like the one from your corner turn signal) or use the technique below.

To use the light bulb, connect it in between the #87 wire from the 30 amp relay and (-)ground. Set the rpm switch at desired rpm (preferably lower rpm for testing only). Start your engine and rev it pass the rpm you've selected at the rpm switch. The light bulb should light up. If not, re-check your wiring from above wiring diagram or ground.

Or set it at high rpm like "5,200 rpm" at the module selector and then take off on second gear instead of first. Or barely use 1st gear like shift at 1,500 rpm and then pop it on 2nd right away and then floor it. It's gonna lag a lil' bit and might even die but the key here is the floor it all the up to 7,500 fuel cut off. You'll feel a slight pull or G's from 3,500 to 4,400 (lower cam profile)and then drop but once it hit 5,200 rpm (high cam profile) you'll feel another set of G's if the vtec controller works. Sohc vtec low cam profile power starts dropping at around 4,500 to 4,600 rpm so if your vtec is not working , you can tell if the engine is not making anymore power beyond 5k rpm.

Or you can hook up an l.e.d. light (like the one from your car alarm) "in between" the relay (#87) and the solenoid permanently installed at the desired location , by the instrument cluster or center console to be assured that your vtec works all the time when rev at the desired rpm.

We set ours at 4k at the track since we launch at 4k to 5k on slick tires of course so that vtec is activated already .But for everyday driving, set it at 4,400 or 4,600 for smooth switch over of the vtec effect. The results might be different on other cars depending on your set-up.

Good luck and enjoy your vtec powered civic or crx,

Mechanic_B and Lagboy
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Considering that the OP hasn't clarified which specific ZC he has that copied/pasted post above may not be 100% relevant and may cause confusion. Having said that...

OP can you confirm which ZC you have? SOHC/DOHC? VTEC or non? Fuel injected or carb'd?

There's really only a couple of minor variances among the SOHC versions that may have you scratching your head, but the older browntop twincam version is the one that won't "drop in" so to speak. It doesn't sound like you are getting a twincam anyway so you should fine as far as the physical swap goes.

 

As far as smog goes, I swapped a d16y8 in and the smog tech didn't notice and he passed me. The legit way is to take it to a state referee and get the car BAR'd. (in CA, at least)

 

wow that is a lot to read above.

habanerored06si, can you show me where you got this info from so I know its legit that way I can start tearing this stuff up. it would be nice if there is a youtube video out or a step by step with pictures to show me what they're doing.

24ten, i have the stock d16a6, fuel injected. the link im going to show is the one im going to buy since its the only one that have that is similar to my stock d16a6. I just want to have a replacement motor to replace my old one and pass smog ok.

http://www.hmotorsonline.com/shop/sc...age&item=30020

fieldgen, i might give it a try after everything is done since it looks exactly the same as my d16a6. im in cali by the way.

 

I have a 1988 crx si 1.6...

 

Bump

 

I'm swapping to a D16Z6 SOHC V-tech into my EF. Where do I look for the wiring conversion kit? I would also like to be able to do this Cali legitimately.

 

why u thread jacking me. all i wanted to know was a simple nonvtech d16zc swap...

 

bump

 

Have another question in mind.

If I buy this motor and use everything that is included such as the dizzy, intake, etc. would I be able to pass smog in california? or i NEED to use the long block only. help.

http://www.hmotorsonline.com/shop/sc...age&item=30020

 

That particular ZC is nearly identical to the D16A6 so it should be a literal one for one swap. Technically speaking, it "should" pass California emissions but it'll be hit or miss whether or not you'll get called for visual. Even then, I've heard both ways that a referee will and won't let you use that engine. Best bet is to contact your local referee station and get the information directly from the man himself (or woman...).

 

Monkey, just completely ignore the post he made.

A lot of that info is "ok" however, it is from over a decade ago hence 2002 in the quote.

If you happened to follow that method, you would visually fail smog check without a doubt.
In current times, there are MUCH better ways to install the motor using the PROPER ECU.
There is no need to hack up the distributor, use the wrong ECU, and buy a vtec controller.

 

so which proper way or better way to install the motor? I mean, I just want a replacement motor, not tweaking it or anything. my engine is almost 300k miles and i just want the thing to work again by doing it myself if possible.

 

Check what 24Ten had to say.
That is correct info.
That motor is identical to your stock motor so there is no wiring or anything to be changed.
California considers many imported motors as direct replacement even though the stamp on the engine is clearly not the original USDM. Call the referee or visit a test only smog place and see what they say.