How about the D16Y5 (HX motor)?
 

You hear SO much here about the D15Z1. But NOTHING about the D16Y5 (1996-2000 Civic HX motor). This motor was built with basically the same uel economy goals as the D15Z1. Yet you NEVER hear about it here. This motor seems quite attractive, given its newness and 23 extra HP compared to the D15Z1. Yet, you NEVER hear about the D16Y5 here, or, for that matter HXs. Is this motor just not very good when it comes to fuel economy?

StorminMatt -

We have had some HX owners, they're not just very vocal. I have also wondered why there haven't been many HX'ers. Here are the only ones I could find :

The HX-Back in Black
https://www.gassavers.org/garage/view/338

01HondaCivicHX
https://www.gassavers.org/garage/view/530

97 Civic HX
https://www.gassavers.org/garage/view/731

When I saw the last generation 2000+ HX's on the lot in SoCal, they were rated at 36/44 EPA, and offered lean burn modes. I would guess that they were not as good as the previous VX'ers because of increased emission standards.

Psyshack was looking to get a last-gen-HX used, but they are hard to find in good condition with low miles.

CarloSW2

I think that a BIG part of the fuel economy problem wih the HX is weight. By 1996, the Civic was well on its way toward becoming the clinically obese beast that it is today. A typical Civic sedan of the time weighed 2500-2700 pounds, depending on model. And this is NO way to get good fuel economy. On the other hand, I was thinking more about the D16Y5 as a swapping motor. PLENTY of people swap the D15Z1 into cars like CRXs. But you NEVER hear about D16Y5 swaps. Of course, some of this is inevitably due to the more complex OBDII electronics. But it is still quite doable if you use 1996-1997 electronics. Also, the prospect of a very economical car with over 20 more HP than a D15Z1 sounds interesting.

VX are older, cheaper, and come in the hatchback version.
HX are newer, expansive (imo, 5k+) and come in coupe version.

Maybe people here are more on the cheaper and hb thing, still there is some HX on the forum. But I thing HX is good, but not better than a VX BECAUSE the HX his not only made for fuel economy, because if you go on the high rpm range (5000 or so, I don't know), the engine is set for performance.

Anyway, I don't like coupe, not as usufull as a hathback, but thats my taste.

I've also been asking about the HX. Never owned a Honda but maybe for my next car. HX is not easy to find but is newer than the VX, and since HX started in '96 it will let you use a ScanGauge.

I've seen them offered as low as $3500 by private sellers and small used car lots. But often between $7-10K which takes it out of the picture for many people who don't like debt.

I understand the HX is heavier. Personally I appreciate the assumed increase in safety but that's just my own view. Coupe should have better aero than a hatch but that's another judgment/preference thing.

The D16Y5 is a good motor, it's just packaged incorrectly IMHO.

The big problem with swapping that motor into a VX chassis, let's say, is the fact that the Distibutor Plug is way different, and the crank angle sensor location is about as far away from the VX location as you can physically get. Couple this with the fact of having to change out or make your own adapter for the ECU connections (nobody makes a plug and play setup as of yet for that particular swap) because the P07 ECU wouldn't take full advantage of the D16Y5 setup and you have yourself a pretty large mountain to overcome just to get that motor in your car.

There are tantalizing things about the swap though. The motor physically will drop right in and will bolt up to the VX trans (which is geared a bit more towards FE than the 5 spd HX). The extra power would be great for on ramps. With the VX gearing and extra power, you would still be able to pull off Stock VX EPA numbers, if not, better.

This has been a swap idea for my VX since the day I got it. The thing that held me back was the fact that I had a low mileage spare d15z1 fall into my lap for free. So I'm in the middle of rebuilding the free block (just so it's fresh and I can tweak some things on it) and going to install it in the springtime.

I also think the obd2 aspect makes the HX motor less desirable. The engine sensors are something you can get past, but the ECU using a different plug compared to the OBD1 civics would be the most annoying aspect for me. You could make an adapter with some junkyard plugs, but I would only go through that hassle if the motor was cheaper than the d15z1 (which I haven't found it to be yet, but I might start looking for a $50 or less one just to possibly look into doing this swap).

Of course, my thoughts were more about swapping this motor into a 1988-1991 Civic. With this swap, you would have to change the wiring regardless of whether you go D15Z1 or D16Y5. So the difference in difficulty would be smaller than on a 1992-1995 Civic. Yes, there really are no adaptor harnesses. But I hate those anyway, and prefer to just cut and solder ECU plugs from the junkyard.

I'm pretty certain you can have a custom adapter harness made at rywire.com. They'll make anything for you.

That being said, if you're swapping the engine, why not just bring the new harness with you? You will probably have to get a new cluster and some other stuff, but you would be totally obd2.

I've done PLENTY of Honda engine swaps (including my ITR swap, which is quasi-OBDII). And I can tell you one thing: swapping over entire harnesses is definitely the HARD way to do the job. Not only will the cluster need to be changed. But it is VERY likely that MUCH of the electrical system will need to be changed as well. This includes the fuse panels, along with the HVAC controls. And let's just see how easy it will be to make the newer instrument cluster fit into an older dash. This does not even take into account the fact that (1) many of the connectors will not bein the proper location, and (2) you will possibly not be able to properly route the wiring. It is FAR, FAR, FAR easier to make the necessary modifications to the original wiring harness to accommodate the newer motor/ECU than it is to try to change all of the harness over. Trust me on this one.