Bense's H23A Swap HowTo & Discussion Thread.

The purpose of this thread is for me to post pictures, discuss my findings, address the obstacles that I will need to overcome, exchange ideas, and to serve as my rolling write-up of how to perform this engine swap. Once I have completed all tasks, and have sufficiently tested this setup (for a few days), I will organize, clean up, and make a post with a concise, procedural step by step outline on how to perform this swap. I will continue to edit and update this post to keep everything as clear and concise as possible.

I will provide as much associated information/media/documentation/data that I am able to post. However not freely providing to the public something that was given to me may become a constraint. If this is the case, please respect that.

Additionally, due to the days of users with 56k modems being long gone, and the fact that most users will be viewing this with a screen resolution such as 1280x800, 1366x768, 1920x1080, 1920x1200, along with a "broadband" internet connection, I will be very liberal in posting full size images. I will try to display images that are less than 1200 pixels wide, as well as provide a URL below to the full size of the image.

Moving forward.

Objective: To document the progress of my process of replacing the original F23A1 engine with a "Blue-Top" JDM H23A DOHC VTEC engine.

Vehicle: 2001 Honda Accord EX 5MT

ECU/ECM Engine Management: I have the OEM H23A ECU for an automatic transmission. If there is a feasible method in which I can use this with my manual transmission, I will use it. If this proves to not be a viable option, I have the equipment to convert to OBD1.

Moving on to pics..

The H23A that I have received.

Full Size: https://lh5.googleusercontent.com/-...XjAX-zlc8KM/s3289/h23a_02_20140702_144959.jpg

Block stamp:

Full Size: https://lh5.googleusercontent.com/-...4bthxDJt22c/s3320/h23a_04_20140702_144406.jpg

Head stamps

Full Size: https://lh3.googleusercontent.com/-...NmQfgaUbx3U/s3476/h23a_05_20140702_145025.jpg

Intake manifold view

Full Size: https://lh4.googleusercontent.com/-...2zgAwtmC3vg/s4128/h23a_06_20140702_145033.jpg

Timing belt, crankshaft pulley view. Note the single channel crank pulley, along with the aluminium bracket that goes between the drivers side chassis mount and the cast steel "timing belt" engine mount bracket. Will having this bracket alleviate me from having to modify the cast steel "timing belt" mount? Hmm.

Full Size: https://lh4.googleusercontent.com/-...UjoWbnPutv0/s2959/h23a_07_20140702_145105.jpg

The H23A IACV (Idle Air Control Valve) is 3-wire, like the F23A1's IACV. If I am to convert to OBD1, how will I get this working?

Full Size: https://lh6.googleusercontent.com/-...AAAA9Co/d-KFj5ooPfA/s1250/20140713_163707.jpg

The H23A PCF ECU

Full Size: https://lh3.googleusercontent.com/-_foWtVoOShg/U8MHjWGG13I/AAAAAAAA9DM/Sp-urzUk4fg/s1600/pcf_04.jpg

PCF ECU PCB (Top-View)

Full Size: https://lh5.googleusercontent.com/-ZskHbpOoLBg/U8MHiJu5kPI/AAAAAAAA9DE/idopswLPit0/s1600/pcf_01.jpg

PCF ECU PCB (Bottom-View)

Full Size: https://lh6.googleusercontent.com/-cfdKXLayX9s/U8MHik8kRYI/AAAAAAAA9DI/akEf52U2ems/s1600/pcf_02.jpg

PCF ECU PCB (Plug View)

Full Size: https://lh6.googleusercontent.com/-6l3OChD5U6w/U8MHieh5PJI/AAAAAAAA9C8/CuuTxMubSzE/s1600/pcf_03.jpg

Test mule

Full Size: https://lh5.googleusercontent.com/-...0I/AAAAAAAA9CM/UXvMGRfjp24/s3264/IMG_4284.JPG

The dirty

Full Size: https://lh4.googleusercontent.com/-...YI/AAAAAAAA9CU/7Pb_YO_LcsE/s3264/IMG_4289.JPG

Subscribed!

Happy to see you doing this and hopefully documenting as well as you said you would. Please make sure pics stay hosted for future viewers. Nothing worse than threads with missing pics. Will be following your progress man!

Somebody on here tried the auto ecu and tricked it to thinking it was in drive to get rid of rev limiter but he had trouble starting it all the time, why not pick up a 96+ prelude h23 like this(click here)

i just found this thread with a lot of info about running a manual h23 obd2, click

this seems helpful

Ok there are 3 correct ways to solve this problem.

1. You can simply use a JDM or USDM 96 prelude ECU VTEC

2. You can use a reprogrammed P28 ECU

3. You can use any JDM Prelude ECU

Because you want to keep your car OBD2B, The JDM ECU is your only choice.
97-01 USDM ECUs are equipped with the Anti-thift Immobilizer that everyone claims that they can remove. It won't work and is illegal, and even if it does, the ecu will be more confused than a naked girl and a virgin.

Not only the JDM ECU is the correct choice, its the smart one. Not only it doesn't have a immobilizer but it also lacks in emissions components that the USDM ECU have.

For performance Junkies and the people who don't really give a **** about the emissions and laws, the OBD1 is the way to go. OBD1 is the way to go because it provides the ability to be Tuned. Stay AWAY!!!! From OBD2 unless you have.

Hope this Helps everyone...

Click to expand...

I hope the link i provided you with will help you in this detailed journey, hope you stay true to your word and will be very detailed. Overall good luck with your swap

F20Bs don't take prisoners they chop faces off!!

AFAccord said:

Subscribed!

Click to expand...

Thanks Jason!

cmgreensr said:

Happy to see you doing this and hopefully documenting as well as you said you would. Please make sure pics stay hosted for future viewers. Nothing worse than threads with missing pics. Will be following your progress man!

Click to expand...

At 31, I don't see much use in talkin' the talk if you ain't walkin' the walk.

One of my most recent projects was building a workstation which has redundant data storage, so that I don't lose any data.
http://h30499.www3.hp.com/t5/Workst...s/BenseBuilt-XW8600/td-p/6386575#.U17Qf_ldWSo

I've then got my images synchronized in the cloud with my dropbox account, and the ones that I linked here are to my google picasa account. I have learned to not rely on companies such as photobucket. Although, (surprisingly) my previous Accord Euro R Intake Manifold post where photobucket is hosting the images, looks the same as it did 7 years ago. http://honda-tech.com/showthread.php?t=1960750

If you or anyone else ever have problems with dead image links, please contact me and notify me. Looks like now is a good time to update my signature...

Brad2274 said:

Somebody on here tried the auto ecu and tricked it to thinking it was in drive to get rid of rev limiter but he had trouble starting it all the time, why not pick up a 96+ prelude h23 like this(click here)

i just found this thread with a lot of info about running a manual h23 obd2, click

this seems helpful

Click to expand...

Would that ECU be for the H23 DOHC nonVTEC?

Do you know off hand how I might find that thread on how he tricked it into thinking it was in drive? perhaps that could be wired in with a simple relay to toggle on/off...

Thank you for the links. The thread on honda-tech seems inconclusive

f20bcg3 said:

I hope the link i provided you with will help you in this detailed journey, hope you stay true to your word and will be very detailed. Overall good luck with your swap

F20Bs don't take prisoners they chop faces off!!

Click to expand...

Thank you for your help.

I actually took the time to check out your links/writeups very detailed and explicit hope this turns out the same way good luck

F20Bs don't take prisoners they chop faces off!!

I'll subscribed since I plan on doing this in the future now that I don't drive my Accord daily anymore!

Once again, Rosko (Rosko Racing) has managed to help me out by sending me a mystery box of random F/H gears. Here's what I have found.

Assuming that the values listed in these tables are correct http://honda-tech.com/showthread.php?t=2548441

Rosko Mystery Gear Stack #1 - JDM Prelude Si - M2K4 - H23A1/H23A2
1st - 43/13 - 3.307
2nd - 38/21 - 1.8095
3rd - 33/26 - 1.2692
4th - 29/30 - 0.9666
5th - 26/33 - 0.7878
FNL - 65/16 - 4.0625

Rosko Mystery Gear Stack #2 - USDM H23A1
1st - 43/13 - 3.307
2nd - 39/21 - 1.8571
3rd - 33/25 - 1.3200
4th - 30/29 - 1.0344
5th - 26/32 - 0.8125
FNL - 64/15 - 4.2666

My F23A1 Trans
1st - 46/14 - 3.285
2nd - 47/26 - 1.807
3rd - 37/31 - 1.193
4th - 28/31 - 0.903
5th - 24/35 - 0.685
FNL - 65/16 - 4.026

I now have the H23A1 3/4/5 and the H23A1 final drive of 4.266 in my F23A1 trans. Although I'm considering placing that 0.787 5th gear in.

4th -> 5th gear reductions from H23A1 4th gear
1.034 -> 0.8125 = 0.785
1.034 -> 0.7878 = 0.761

Hmmmm...

If you do trick it into letting you use the auto ecu, let me know if you somehow manage to pass emissions with it. I've been curious to see if it can be done for a while, or at least with an obd2 h22 ecu.