I purchased this motor not knowing anything about it, other than it's a Euro Accord Motor and the car company Rover in Europe used this Honda motor in their vehicle. This Motor has the same specs as the H23a1 and so I would like to know from the people who have swapped this engine in their Prelude if it's an easy swap? What the difference between the H23a1 and H23a3?

I will let you guys know beforehand that I looked on this site and found 4 pages of the same useless info on what this engine IS, not how to swap it or what to look out for. That's what I want to know. If you have any info please share. Please don't give me any links because chances are I already saw that page.

 

From everything I've read, the H23A3 is identical to the H23A1, making it a straight drop-in. I cannot quote sources.

The H23A3 came in the 1993-1995 Accord 2.3i SR (CC7, EuDM). You can compare its manual to the manual for the 1992-1996 Prelude Si (BB2, USDM) manual and check for any differences.

 

Thanks for the info but I am not really going to read all that information to find out it's the same.

I want to find out from the people who actually have this motor or have swapped it in to let me in on what was done to make it drivable without the engine light on.

This engine has no knock sensor and so the USDM ECU will give me an error code. I could get it chipped so it eliminates the error code, but there's gotta be an easier way.

 

So no one has ever swapped this engine in a prelude??? I find that hard to believe...

 

You don't see many EDM motors floating around.
I've never heard of someone using that motor. Usually they'll end up with the JDM F22B.

 

My friend 'saikou' put one in his 4th gen. It was exactly the same as an H23A1 except for the valve cover.

 

So he had no engine codes go off due to a lack of a knock sensor? From the knowledge that I've gained, the ECU for the H23a1 will look for a knock sensor and so it will go off if it doesn't find it. Is this Saikou still around? I'd love it if he had some input on this.

Here's what I know, some true and some I still am unsure of:

Yes, the valve cover is different
NO knock sensor
Oil cooler in the back of engine
Distributor has an external coil instead of internal
Wiring harness may be a little different
Exhaust Manifold is different
Power steering bracket will not clear the engine bay,so you need to use the H23a1 one.
Oil pressure sensor located on H23a3 where the knock sensor should be on H23a1.

Again, Can anyone prove these facts? Only those who have done this swap.

And KreLude, Well now know someone who is using this motor.

 

What you said is pretty much true. I bought my H23A3 motor from Hmotorsonline and swaped it in. It pretty much is like a H23A1 motor but w/ the little stuff like you mentioned. You might want to swap the Intake Manifold from your H23A1 motor, the vacuum ports are different from the H23A3 intake manifold. There's no Knock Sensor on the H23A3 motor, so you have to swap that in, but if I'm not mistaken, the oil pressure sensor is below the oil filter, whereas the knock sensor is above the oil filter. I believe I used the same exhaust manifold that came w/ the H23A3 motor as well.

Pretty much what you should do to make your life easier is just to swap the parts that were from your H23A1 motor to the H23A3 motor. You should still use your H23A1 wire harness.

Pretty much is a H23A1 motor.

 

or they go to the better route and put a H22 in. lol.

 

Yeah, he could be. Send him a PM...I really (obviously, lol) don't know all the details but he would probably know a bit more.

 

Yeah I'll try to let him know. I'm just surprised no one has ever done this swap lately or for the people who have done this swap, why not make a write up?

Thank you. That's the type of experience I wanted to hear. Alright then, I'll swap this thing in and let you guys know the result. Any one else have some input?

 

Generally the blocks are mad the same just pull thee metal plug where the knock sensor goes and put in your knock sensor. All prelude's pre-obd2 are external coil also you might have to change your fuel rail out considering it could be backwards if the car it was in was RHD

 

JDM H22s are not external coil.

 

Thanks for the heads up. I am going to change the rails and distributor. I'm looking at the Exhaust manifolds but they look the same. How can they be different?

 

They could be the same but depending on what car they were on the flange could different or the length of the down pipe after the bend could be different. I learned really quick when your dealing with metal close doesn't count. I had a F20 it's a dual cam non vtec and it had a plug in the block for the knock sensor. You could throw a check engine anyway though depending on the egr setup and emissions.

 

I don't care about emissions anyway. Just so long as everything runs smoothly. I am Only using the head and the block from the H23a3 motor. My alternator on my H23a3 is busted, do you guys know if the H23a3 one runs the same?

 

probably, but why would you use a busted H23A3 alternator instead of the one on your H23A1 motor?

like I said earlier, just swap everything that makes it look like it came from your H23A1 motor and you'll be fine.

Even though I know you're trying to be careful and taking every precaution, you're making it sound more difficult that it really is. lol

 

Oh I meant H23a1 Alternator got busted. Yeah well For a car that I got lied to and ****ed over with when I bought it, I don't want any screw ups. I'll swap this in and let you guys know later today or tomorrow.

 

Like everyone mentioned above, the A3 is nearly identical in every way - just swap the intake manifold and your golden. Its been about 2 years, but I do believe the A3 doesn't come with a knock sensor, so you'll need to swap yours in. I think someone mentioned that above too.

If you can drop the original motor out of your car and label all the plugs and remember where they go, you won't have any problems (plug & play).

 

Well placing the engine in was pretty easy, there was no issues, and no need to change the PS bracket. I only had time to swap this motor in but not actually wire it back up, so I have no idea if it starts. Didn't use the intake manifold or fuel rails. But I am using the Exhaust manifold.

My knock sensor from my H23a1 was broken (WTF?) so I had to go to a parts shop and find out that the price for this tiny thing was more than $150. SO I said screw that and looked online to find out that I can use a ITR, CTR, Prelude SI or Vtec, and apparently the 92-94 Acura Vigor(which I lucked out on b/c there was actually only one in my local junkyard.) SO I copped it and it looks the same and everything, hopefully it's the same. I think my Alternator is busted on both engines but I need to glance at it again.

Oh and hey Saikou, What about your Distributor? Did you replace the a1 for the a3 or kept the a1 in the car and placed it on the new motor? I think the EDM one is missing a blue wire or something...

I am on a trip to Mexico and will have to postpone my result til I come back next week.

 

Use the distributor from the H23A1 motor

 

^^ yup, forgot that too. Man, it's been so long. Glad you got the motor swapped in. Now get that ish started.

 

yea, its been about 2 years for me too when I swapped mine in.

 

Update: Motor is swapped in!! And it runs.



As you can see in the picture, the engine bay is a little tight on the right side . The brackets are different, and so there was no clearance for PS, and I want PS. Looks like the rumor about the power steering bracket was true, So I just had to use the old one.

In the pic you see the distributor from the H23a3, yeah don't use it. I replaced that later.


Other than your usual funky idle from a motor swap, it runs fine.

Thanks for your help guys.

 

This thread waz fun to read. Nice swap and gratz