casedood2k4

Hey guys,

I am swapping the motor in my 4G prelude yet again. First, two years ago, was just a JDM H23A1 into the car after a tired H23 was removed but now I am going for the blue top swap. I would like to think I have done the majority of my research and am only asking for reassurance and clarity, not advice, so please keep the "check the existing threads" bashing to a minimum.

I currently have a 5-speed 1995 Prelude SE with H23A1 non-vtec. I intend on purchasing this motor - H23A DOHC VTEC BLUE TOP LONG BLOCK and converting the set up to OBD I. I will be using the existing H23 harness and running my wires for vtec.

I already have in my possession or intend to purchase the following:

• H22 OBD I intake manifold and sensors (IACV, TPS, IAT). I will swap the TB from the blue top to this set up. This deletes the FITV.
• H22 OBD I injectors. I will install these on H23 fuel rail.
• H22 K-Tuned Manual Tensioner (link)
• P28 ECU with blue top basemap
• ODB I/ODB II Distributor Jumper (link) Is this the correct jumper? Please see concern below.

My main concerns/questions:

1) I intend to use the ODBII dizzy that will come with this motor with the jumper harness rather than putting on an OBD I H22/H23 OBDI distributor. This will work, correct?

2) I have read mixed things about power steering. It seems the consensus is that if I want power steering to work with the blue top I will need to acquire H22 mounting brackets for PS, alternator, and AC as well as H22 crank pulley. Can someone please confirm this is true or partially true? If so, if I drop this motor in as is, I will not have PS but could have AC?

3) I intend to delete the EGR and rewire the knock sensor.

4) Can use my H23 headers I already have or the H23A blue top exhaust manifold that will come with the motor. Is one any better than the other?

When I get the motor I intend to replace the following seals: cam, balance shaft, rear main, crank, oil and water pump as well as a new timing belt. Please let me know if I covered everything that I will need to do. I plan to order any parts I do not currently have and have them ready to do the swap this upcoming weekend and would like a few surprises as possible.

Thank you for reading! I appreciate any information or feedback you can provide.

1991_crxsi

iTrader: (1)

I don't think so, but I could be wrong. I know that you can do it on a B series, but I don't think it works like that on an H. There was a thread about a guy trying to do this and it went on and on for weeks... I don't think there was a definitive method spelled out but I'll see if I can find it.

Definitely that is one way to do it. If you drop it in "as is" then you can run A/C but no power steering so long as the A/C lines match or the compressor that is in the car matches the one on the H23A and the configuration physically fits in the chassis. You might be able to fabricate a bracket for the power steering and then run a different belt... just an idea. I would just swap over the H22 stuff and keep it OEM-ish.

okay

The H23 headers have a different bolt pattern, and the ports are different so they will not fit. The PLM Try-Y performs really well with the H23A Blue top and is affordable.

Just delete the balance shafts instead of replacing the seals. Worth a couple ponies. Also the KS timing tensioner is a good mod that is fail proof when installed correctly... unlike your OEM tensioner that will almost certainly fail eventually.

casedood2k4

Thank you for the information. I still have yet to obtain 100% understanding for the distributor. Most folks just state "use H23/H22 dizzy". I have an OBD I H23 dizzy from the H23A1 that I do not have any issue with swapping to the blue top and then I would not have to buy the jumper harness, however, will there be an issue with the crank sensor then? Most of what I have read folks end up throwing information regarding oil pump, crank sensor, and dizzy all in one illogical run on sentence and I have yet to understand what one component being swapped means for the others.

I am looking into both the PLM Try-Y Headers as well as the balance shaft delete. I may end up doing both of those another time due to financial constraints and the minimal time I have available to complete this swap. I am definitely doing the KS manual timing tensioner. Will the H23A blue top exhaust manifold that comes stock bolt up to a USDM H23 down pipe?

I have read that the knock sensors are different - one is square and one is a circle? Am I going to have to acquire a plug from another resource that will work for this application using the USDM H23 harness?

The data I am providing to the ECU folks are: blue top with stock internals utilizing stock H22 345cc injectors. VTEC engage at 4600 and rev limiter at 7100. Would you suggest that I have them disable O2 (open loop) as well? This is my daily driver and I want it to last but have a little pep - does this sound like a good set up?

casedood2k4

Just finished the swap last night and fired it up. Going to do a summary of my swap including issues I encountered, things I expected and did not expect, and try to clarify some of the uncertainty with this swap. My intention is to have a reliable daily driver so I kept nearly everything stock. If I do not mention something explicitly then I determined it was unnecessary to swap or I just haven't realized I need to yet.

ODB II H23A VTEC being swapped into an ODB I '95 Prelude with H23A3 and M2S4 transmission. I did not swap oil pumps. I did not rewire any new sensors. I did not delete the balance shafts. I did use the KS manual tensioner. I mounted my coil to the top of my starter. I had to extend the wire for VTEC solenoid that was prewired from the ECU (pin A4) to the passenger strut tower. Anything mentioned below as "H22" or "H23" are assumed to be from an OBDI vehicle.

ECU: P28 with basemap. Deleted O2, EGR.
Distributor/Coil: H22, H23
Injectors: H22
Fuel Rail: H23. H22/H23A will work with modification.
Throttle Body: H22, H23, H23A
Upper Intake Plenum: H22, H23
Intake Studs: H22, H23
Fuel Rail Studs: H22, H23
EGR: Deleted
Thermostat: H22, H23, H23A
Exhaust Manifold: H22, H23A
Downpipe: H22, H23A
P/S Bracket: H22 or modified H23. I used a sawzall to cut off the piece that very clearly prevents the H23 mount from being used.
Alternator Bracket: H22, H23, H23A
A/C Bracket: H22, H23
PS Pump: H22, H23
Alternator: H22, H23
Compressor: H22, H23
Driver Motor Mount: H22, H23
Crank Pulley: H22, H23

Hope this information helps anyone that does this in the future.

Pic of engine bay post-swap