So, I recently traded my '90 integra 4dr for a 4th gen prelude SI. Has a h23 with a spun rod bearing. My question, what's the cheapest fix? I'm 17 and doing this for cheap(I don't have a license so I have time for a project). So far it's looking like 600$ for all the parts to rebuild the motor, or I can buy a jdm h23vtec for 900$. Another question. What ecu is my lude. Obd1 or obd2? I want a vtec badly and have found very cheap motors before around here. Any help?

 

its obd2 and save yourself the hassle and just get the h23vtec

 

4th gen preludes range from years 92-96. 92-95 are obd-1, 96 is obd-2. An h22a would be a better choice, because you can source one that is obd-1 and not have to deal with converting over from an obd-2 which is what you would be doing if you went with the h23v.

Research is key.

 

Thnks. I haven't been able to find that answer at all. I've researched a ton, idk why but I couldn't find that info anywhere. What all would I need to do that swap? I've seen the swaps turn out being 1600$ and above. I don't have that cash. I gotta do this cheap as I can. I found an h22a4 that is blown. The head is good an the crank might be also. Does the h22 crank interchange with the h23 block? Sorry for all the questions. I'm trying to learn as much as I can bout these cars.

 

h22a1 cranks interchange with h23a1 since these used the same block, but most of the a4's had a larger main bearing journal so they won't fit. How bad spun is the rod on the h23? I'd take the pan off and the rod caps loose and see if the crank is shot. Unless it is physically damaged, I believe a good engine shop sould be able to clean that crank up and you could rebuild the h23 no problem. What are your goals? Most people seem to be after more power but if you just want a working car that is probably the easiest way. Or if your looking for a swap, the jdm h22a is a more common and easier swap. Or an h22a1. The h23v and h22a4 swaps are possible and have been done, just more involved.
GL
Mike

 

Your easiest swap besides replacing with another H23a1 would be a plain JDM H22. All you would need to do is swap it in, use your existing harness and add a few wires for vtec. You would need the engine itself, intake manifold and injectors, header and the P13 vtec ecu. You have to have the P13 ecu in order for it to run right. Anything else like distributor(minus plug wires), alternator, p/s, a/c you can reuse from your existing motor.

If you went the bluetop H23a route you would be stuck with running an H22a1 ecu or getting a P28 and tuning (the right way to do it but more $$) I DO NOT reccomend trying to run an H23a bluetop on an obd1 h22a1 ecu and impossible on an h23a1 ecu, compression is different, stroke is different, piston speed is different which all effects the tune and how the car is setup. You always want the injectors and ecu to be matched up for the motor its running otherwise you will be either too rich or too lean or have incorrect ignition timing for the stroke/compression and dynamic of the motor. Don't try to run an H22a1 with h23a1 injectors or vise versa. With a JDM H22 you will somewhat go against this rule because the JDM h22 has slightly more compression but it uses the same injector size as the usdm H22 ecu and all else is equal so you can get by using the usdm P13 ecu since that will be more readily available.

If you wind up going with an obd2 H22a4 keep in mind it also has different fuel injectors so you'd want to switch those out for obd1 injectors if you are going with the obd1 P13 ecu.

Again, easiest route would be either a JDM h22a and then sourcing a usdm P13 ecu, or sourcing a usdm H22a1 with a P13 ecu. The 96 motor is obd2 even though its still labeled an H22a1 so its going to have the different ecu and different injectors so I would stay away from that one. Rebuilding what you have is an option but it takes money any time you tear a motor apart (gaskets/bearings/rings/machine work)




The cranks are a different stroke so its not an accurate statement to say that they interchange. Yes, if the main bearings are the same diameter (50mm vs 55mm) the crank will drop into the block, but an H22 crank is not a replacement for an H23 crank and vise versa.

If the H23 crank is damaged then thats probably an easy fix for a machine shop using oversize bearings, but most likely its a spun main bearing which in turn tears up the block on its way out. Still fixable to an extent but now you are spending alot on machine work and most shops arent capable in my opinion of doing this as accurately as it needs to be.

 

Wow guys thanx alot. That all is super helpful. And mike, as of my goals for it, it just needs to run. Later on (year or two down the road) I want to boost an h22 (forged rods, low comp pistons, ect) but for now I just need to make my car run so I have something to drive when I get my license back, but If I can swap a h22 into now for less then or equal to $1000, then I'll just drop one in, I just needed to kno the parts needed for it. The interior/ exterior are gonna be cleaned up and redone. The car isn't getting just a cleaner up motor, I'm putting all new custom interior in it. Good sound system, nothing extreme though. Then it's gonna have a two tone paint on it. I'll post pics of the car when it's done. If anyone else has any suggestions/ comments im open to it. thanx again all. That all helped alot

 

So, then I would need the p13 add on? I just re-read the post and realized I had read it wrong. H22, P13, h22 injectors, extra wires for vtec, what else? Or is that all? I'm gonna start putting my parts list together for the h22 swap. Sounds like I can do it for under $1000

 

I am sorry Rosko, rereading my post I did not make that clear. The main point I wanted to make was that the a4 crank will not physically fit in the h23a1 block. Yes, if you change the crank you will need different rods and pistons to make it work. To the OP, please research these blocks and the FRM sleeves and how they will not work with aftermarket forged pistons, and the general concesus that to run forged pistons you have to re-sleeve. I agree with Rosko though, keeping OBDI parts throughout will keep this easier.
Good Luck

 

Just as a question Rosko, what makes you think its a main brg? I'm assuming you have seen these failures. I haven't been into a bunch of these engines, but the one h23a1 I took apart not too long ago had 2 spun rod brgs and the mains looked ok. All the bearings were shot, however, many through the copper layer. I'm just interested, cause I know you've got WAY more exposure to this stuff.

 

So for sure what do I need for the swap assuming I keep it obd1?

 

I guess just because I've seen more main bearing failures than anything else, could just be a coincidence though. Chances are though if one is bad then everything is bad. Several years back I was searching for a good block to build, two blocks I purchased bare online had main bearing damage and two complete engines I picked up locally had main bearing damage when I tore them down. I've personally had one main bearing failure/busted crank on a race motor of mine and the very original motor out of the car had a rod bearing spin on me shortly after I got it (thats what got me into this whole mess of Hondas lol). So I guess thats a ratio of 5 to 1 from my personal experience on main failure vs rod failure. I've also torn down a few motors with trashed cylinder walls.

 

H22a longblock and a P13 ecu, give Steve at hmotors a call and he should be able to hook you up with what you need. Then all you gotta do is add a few wires and you are set, there should be plenty of info on that floating around here.

 

Sorry for the repetitive questions. And I was Thinking of calling him, but I hear some bad things bout hmotors. I guess if you go through him I can trust it. You seem to be well known on here so.
Anyways, thanx a lot all. I'll probably end up with the h22 if I can. I still have yet to tear my motor apart. That's the deciding factor in this whole deal. If I can fix my motor then I will for now. If I have to buy a new motor(which is what it sounds like I have to do) I'll spend the extra money and do it right with the h22
Thanx again everyone.

 

I am doing the same swap right now. Switching from a h23 to a h22 is easy for the most part. The parts needed are;
A vtec ecu
A header and down pipe as the h23 will not fit. (eBay if your looking for cheap)
Some wire to hook up the vtec sol.
A coil bracket since the way it hooks on the h23 will be in the way of the vtec sol. ( junk yard, Honda discontinued the bracket)
Thats pretty much it man, if you have any questions pm me, I am litterly in the middle of doing mine so I can show you pics or whatever ya need. Good luck.

 

Ohh. Well thanx man. I still don't kno if I'm doing the swap. I have yet to pull my motor apart and see how bad it is. If I can turn the crank and get the oversize bearings, then I think I'll be fine. But if the block is shot, then I'm going h22. If/when I swap to h22, I'll definitely Pm you lol. It'll be awhile before I can pull he motor though. We're building a 4x2 car shop (4cars wide x 2cars deep), I can't do anything major till it's done.
I'm sure I'll end up with doing the swap, seeings as though I'm a horsepower junkie hah anyways. Thanx. I'll definitely pm you with any questions.