i was curious about swapping a d series engine into a 90 integra so it would get higher mpg. i really love the second gen integra and i also love the idea of the civic vx getting like 50 mpg. i know that it will need to be wired for vtec and the five wire o2 sensor but has anybody got any more info on this. any input on this would be greatly appreciated.
thank you jake

Integra up to 93 is cable tranny. VX is hydro. Also, 90 and 91 Integra are OBD0 while VX is OBD1. These are some pretty significant hurdles. Be much easier and much more rewarding to get a 96 Civic or Del Sol and put an HX motor in it.

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The cable/hydro problem can be overcome by using a crx hf transmission or an aftermarket conversion. The obd swap just requires a lot of wiring. It isn't difficult, just time consuming. I agree it would be a lot easier to do a HX into a del sol, but definitely not more rewarding if you really like the teg. There are quite a few people around that have done a z1 into an obd0 civic, myself included. And considering the amount of work you've done to yours suspendedhatch, you're not one to be discouraging. I do admire what you've done though.

Biggest hurdle here is going to be the mounts...they will have to be all custom...unlike the 94+ Ingetra's and 92-95 civics you can't just use the mounts that came from the other chassis...as said before you will have to figure out the trans either going hydro conversion or using the HF or other cable trans, the OBD0 engine harness will plug into the OBD1 motor with only a few changes and a jumper harness at the ECU will allow you to use the P07...

I'd be concerned with the weight of the 2g tegs...I believe they are slightly heavier but I may be wrong...I just did a VX swap into my Del Sol which curb waeight started at about 2300lbs...subtract some weight for the auto trans being removed, power steering rack converted to manual, all A/C components removed, HX wheels instead of steelies..etc I probably have cut some off that off and the Del Sol seems to drive well...I think if your car is too heavy it is going to be a dog...


Good luck and make a build thread here if you decide to go threw with it...

Ninja Edit: Curb weight of a 1990 LS Teg is 2549 (according to Edmunds) ...you might have a tuff time using the d15z1 to pull at least 500lbs more...

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MPG Noob

03 Mazdaspeed Protege
91 Honda CRX Si
95 Honda Civic VX *RIP 5/20/08
94 Honda Del Slow D15z1 Swapped

HF tranny is hard to find and requires custom mounts. It also doesn't have an electric VSS.

I haven't done anything that I would consider difficult (meaning that it requires custom fab). I purposely avoid nightmares like that having learned my lesson in the past. Putting an OBD2 in an OBD1 was more difficult than I thought, and I have had a few bugs here and there. In fact, I would not do it again unless I had money to have some things custom fabbed, ie a throttle cable bracket, a bung for the IAT, etc. Wiring is no problem for me but that is a big hurdle for most people.

I was in no way being discouraging. The facts themselves are discouraging. People are too hung up on the VX motor. The HX motor is superior in every way. It's also more readily available and usually has less miles (along with all the parts that go a long with it).

I love the DA Integra but I purposely shopped for a 92+ because it's OBD1. Unfortunately, I found out too late that it's a cable tranny and that makes the possibilities more difficult and costly if you insist on doing it right.

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Sort of off the subject, but does anyone know of a good summary list of engine swaps that do make sense for a VX engine? For example is it easy to swap into a '92-'95 DX Civic. I am just starting to learn about this stuff. Is there a good source for info on how to make the swap, e.g., what hardware will be needed and pointers on how to do it.

The electric VSS is swappable, people do this for the JDM cluster swap in the EF chassis since the SiR cluster uses and electric VSS...but it does require some additional wiring but it bolts into the trans...

bpack...as for easiest I would stick to 92-95 civics...physically it is a bolt in swap, with exception of an automatic chassis(but we'll get into that if needed), but there is still a fair amount of wiring to do to have the D15z1 run properly in a non VX chassis

I'd say check out my build thread for whats involved, I swapped the z1 into a 94 Del Sol S, Mine was a little more in depth but you can see what wiring I had to do etc, feel free to ask any questions...

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MPG Noob

03 Mazdaspeed Protege
91 Honda CRX Si
95 Honda Civic VX *RIP 5/20/08
94 Honda Del Slow D15z1 Swapped

In which ways is the Civic HX engine superior to the VX engine? Just curious.

Just to clarify, you are talking about the D16y7, right?

D16Y5

It makes more power (hp and torque), has better power band (more power in the driving range), emits less pollution, it pulls a heavier less aerodynamic chassis and drives more accessories, has slightly more displacement and yet it gets similar mileage to the D15Z1.

The combustion chamber design includes more quench area for better burn and resistance to knock. The intake manifold is designed for more low end power where most driving takes place. The OBD2 engines all use a better evap system. The OBD2 ECU has a more advanced tune than the earlier models.

It uses a crank fluctuation sensor for lean burn in much the same way that a knock sensor is used with ignition timing. It will lean out the mixture until it detects misfiring, then back off slightly. This allows for the leanest possible mixture without driveability problems. BTW it also uses a knock sensor.

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suspendedhatch nice info, I wish I would have snagged the y5's I've seen at the local junk yards before...most of the time people pull the heads because they say vtec and leave the blocks to collect water and rust ...

Just out of curiosity if I happen to see another y5 block what are differences between the z1 and y5 head? Would the z1 head on the block have produce similar results? Maybe in the future I will swap my Del Sol to a y5 if you believe it will be a better swap, I'm definitely happy with the z1 but why not if I could produce better numbers...

Thanks

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MPG Noob

03 Mazdaspeed Protege
91 Honda CRX Si
95 Honda Civic VX *RIP 5/20/08
94 Honda Del Slow D15z1 Swapped

So to sum up the advantages in practical terms, if I understand you correctly, the Y5 has more power and pollutes less. I would certainly expect an engine thats 7% larger to have more power and torque. On the other hand, I would then expect the fuel economy to be within 7%, in order to qualify as "similar mileage" However comparing the 96 HX to the 95 VX, the fuel economy is 20% less. If power is what you want, I agree the HX is the better choice, although IMO there are better, but if fuel economy is the overriding consideration, nothing touches the VX. Just my opinion.

Loserkidwac, your swap/project is awesome and I wouldn't change to a Y5 because then you'd have to convert to OBD2 (I would only recommend this to people with a 96+ Del Sol). IMO you'd achieve a better result by pursuing those aero mods you mentioned in your build thread which I always keep an eye on.

The only similarity between the Y5 and Z1 heads is that they use the same cam. All of the Y5's superiority is built into the head design. The only exception is that the CKF is mounted at the crank. In order to use a Y5 ECU, you'd need this sensor so you need the Y5 block.

That is not a fair comparison. You didn't read my post closely because I mentioned that the HX is in a heavier, less aerodynamic chassis with larger wheels and with more accessories driven off the crank (ie power steering, air conditioning was more common than the VX). Take these out of the equation and the D16Y5 gets similar if not better mpg than the D15Z1.

Since we are talking about the D15Z1 vs the D16Y5, you'd have to compare a stock VX to a D16Y5 swapped VX. In that case the Y5 VX would get better mpg as well as all the other benefits I listed to the Y5 including more power and lower emissions. The Y5 is also more reliable. For instance if you have a small vacuum leak on a VX, you get bucking and all kinds of driveability problems. On an HX the OBD2 system is smart enough to back off the mixture and timing so you wont notice any driveability problems; just a drop in mpg and a CEL.

My car is a pretty good example of this. I've already taken this thread way off base and I apologize for that. But I will say that when I'm not tuning the car or driving the piss out of it, I get similar mpg to the stock engine using an engine that is very similar to the Y5.

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