Newbie questions....'91 DX hatch swap

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olde phart

New Member
Been searching and reading.....trying to decide just *what* to do or not do. New to Hondas, but trust me, this ain't my first rodeo on engine swaps, or creating (sometimes stupid) stuff from scratch. I've been driving a (hideously rusty) '91 hatch as a 'winter beater' and over the course I've become really impressed with the little critter; both with the way it drives/handles....and the fact that it's one hell of a lot easier on gas than anything else I've got in my arsenal. So, I got stupid, a found a really, really nice '91 rust (and honest-to God 95% original paint.....I touched up the stone shield and front fascia...). Drivetrain's all stock, suspension is done up right with good stuff....not that cheapo ebay junk. In terms of swaps, I'd really have my cake and eat it too. I don't want to absolutely kill the mileage, and driveability is a major concern, but I'd like it to go like hell on command. After looking at the transmission info....any transmission I swap in here is going to dramatically reduce the end ratio in 5th gear....but I'm not the least bit familiar with any of these other engines other than seeing them go through the shop I help run. I'd like to have something that will still see 30+ if it's drive sanely....does this lock me into looking at stuff that will screw on the transaxle I have.....or is this kind of mileage (again, when it's not being flogged) realistic with a, let's say, JDM b16 eng/trans swap of some sort. Assume...1) Whatever I swap in is gonna' get left BONE tune, boost, juice, etc.; 2) I'm not concerned with having to re-invent the wheel with wiring/electronics; been there and done that with other swaps (ever put a MPFI Ford motor in a Suzuki Samurai? I have...Make sure you put a roll cage in it, too....), and I understand OBDII and have the proper stuff to deal with it.

Hope this all makes sense. I appreciate any constructive input/suggestion/etc.


Why not just go with a ZC? Should drop right in, give you a nice little boost over the stock dx, and should keep the gas mileage that you're looking for. Had one in my crx for a while, but now went for a B20 <-gas hog. I believe you can throw a Y8 head on the ZC also and get you some Vtec.
More (dumb) questions...

How much does the ZC motor share with the stocker in my '91 DX? Will the (fresh) clutch and flywheel fit on it? Are the accessory mounting points on the block in the same locations? It's not a deal breaker, at all...but my DX does have A/C....and it's still charged and working 100% on R12......and my supply of '12' is dwindling, and if a Honda is anything like a Mercedes-Benz, an R134 conversion yields mediocre at best a/c..... IF it mounts in the same location....I just might be able to work around it laying in there, and leaving it hooked up.

Us olde people is really picky about our a/c........especially when the War Department/Significant Other says "it's OK to order that motor, dear".

Gotta' keep her happy. She puts up with me.


The ZC is another D series block- which your stock block is. It's rated around 130hp, and can definitely bolt up to your stock transmission depending on the clutch disc you choose. There are differences between the 88, 89 and 90-91 setups, but most of it has to do with the transmission input shaft. If you go the DOHC ZC route and get an engine with the wrong size flywheel, reuse your stock one and you'll be fine.

The accessory mounts should be pretty much in the same location. If anything, your stock hardware should bolt up ok to it. To be totally safe, get a non-OBD ZC. If you get a newer one (which might be better), you'll have to swap the crank pulley to keep your power steering if your car had it to begin with (88-91 = V drive, 92-95 = serpentine/ribbed). You can definitely leave it the AC hooked up while you change the engine.

As far as converting to R134a, it works really well in a 4th gen. I had the AC on my wife's 88 Civic LX sedan converted to R134, and it blew colder than the original setup. I like my AC literally freezing (the convertible top on my S2000 will be iced over after a long drive), and the Civic was able to satisfy me even after the conversion.
^ This engine's pretty sweet too, but you'll have to do more wiring to get it to work since you'll have to fire off two VTEC solenoids and also run an OBD2 distributor. There's too much to explain about it, so read this article:

And yes, you can drop in a B16A and still get 30mpg+ when not beating on it- sometimes even in the city. But then you have to deal with different engine mounts and a different accessories.

Oh, and the DOHC ZC and the D15B both tolerate turbochargers pretty well- 200whp easily without stressing the stock internals much on a good tune. You could arguably stuff in a DOHC ZC and turbocharge it for less than the cost of a B16 swap if you do the work yourself, and as long as you keep your foot out of it, still get great gas mileage.

Hope that helps.