My JDM H22 build and Swap, incl AT to LSD 5spd.

619rcr · Jan 3, 2013

I have recently completed a swap in my 99 EX Sedan from F23A4 AT to JDM H22A with M2B4 LSD 5Spd. I am making this to go over the details of the build and shed some light on the common questions for those of you who ponder the H22 swap or AT to 5Spd swap. I know I do not have Rep power yet as I have just registered. But I wanna let you know I am an ASE certified Mechanic in 4 Areas and have a degree in Automotive technology from Universal Technical Institute. I hope this will help to explain my level of knowledge. I know the H22 swap has been explained in detail by several members of this and other sites before. But there are a few items I have noticed could be simpler when doing the conversions. :thinking:

619rcr · Jan 3, 2013

Ok so, The current parts on my car include a rebuilt 94 JDM H22A, which I personally removed from a running 94 prelude in Japan. I spent 4 yrs in Okinawa and managed to bring back some treasure. I also have an M2B4 LSD trans also from said prelude. The block was honed and washed before the rebuild.
My bottom end includes Mahle 11.5 to 1 CR Pistons and Eagle forged Rods, Cometic Head gasket, ARP main, rod & head studs and ACL Race Bearings. I have a JDM P13 OBD1 Ecu and Apexi VAFC2 (untuned),Exhaust includes inop EGR, a used DC header I picked up cheap on Ebay, Cat delete test pipe & Skunk 2 Catback. Clutch is Exedy Oem replacement. And my suspension includes Skunk 2 springs, KYB GR2s and Whiteline Solid front sway bar. Other mods include MSD Blaster 2 coil and Weapon R intake.
Future plans are Skunk Pro 2 Cams with titianium springs and retainers, RC injectors, ACT Light flywheel and Exedy Stage 1 clutch. I also will be reconverting to OBD2 to pass emissions.

619rcr · Jan 3, 2013

My car like I said before was originally a F23A4 (ULEV) which many of you know only came AT. The car was purchased for $5k a few years back to replace my wife's 01 Civic when she wrecked it. After about a year the AT trans started slipping bad and the car became my project.

At the time I had an 98 LX 4d 5Spd. I had originally wanted to fix up the 98 and swap in my H22, but looking and the 99 EX it clicked in my head to take the few parts I had on the 98 and put them on the 99. After all my 98 had drum brakes , hubcaps and no moonroof. So long story short I converted the car to MT with mostly OEM parts I ordered from Honda. The swap went well and I drove the F23 feeling relatively satisfied with my M2B4 LSD for a couple years... Mods at the time included My skunk2 Catback and Weapon R intake dropped on skunk2 springs with the whiteline sway bar. I later got a Cheap ebay header for $45 and cat delete for $15. I added a VAFC2 looking for more power and of course there wasn't enough.

Recently My F23 was showing its age. It leaked about a quart of oil every 1000 miles. And it felt so weak even in Vtec. Surfing the web I kept seeing that the H22 swap was rather simple. The hardest thing seemed to be sourcing the motor. My H22 had been sitting in pieces in the garage for several years for lack of funds. I took a few months compiling cash and sourcing parts to do my swap.

Old engine pic

619rcr · Jan 3, 2013

To summarize the parts for AT to 5spd again for those of you who do not know. You will need:
1. The 5Spd trans of your choice. Accord or Prelude
The 98 -02 Accord 5spd is probably cheapest, and easiest to find
92-01 prelude trans work well too, the bolts are not exactly same, I believe 1 does not line up, but it will work fine.
2. MT Flywheel, accord or prelude. I used an OEM replacement for 98-02 accord.
3. Clutch, Accord or Prelude is same. I like exedy, good quality for the price. OEM replacement will work fine for bolt ons and Stage 1 is pretty good for light mods.
4. Shifter, linkage (Honda OEM) from your year and model and shift knob of your choice
5. clutch lines and pedals (Honda Oem) including bracket for Clutch pedal from your year and model. Don't forget smaller MT brake pedal.
6. Clutch master and slave cyls (I used Napa parts, but OEM is best) from your year and model.
including slave cyl mounting bracket from your year and model.
7. MT CV axles and intermediate shaft from your year and model.
8. An MT ECU is not required to start the car, but you will not have VTEC and will not rev past 5k with an AT ECU. So MT Ecu from your year and model is recommended. If your car has immobilizer it will need dealer programming of key. I used an F23 49 state Ecu from a 98 accord. Dealer reprogram cost was $150 or $200. Its been a while.
10. Reverse switch from your yr and model if not included with your trans. I used new honda OEM.
11. MT starter, Prelude or Accord.
I found one of those online Honda parts websites and looked thru the pictures to make sure I got all the various nuts and bolts and misc parts.

619rcr · Jan 3, 2013

AT to 5Spd Swap wiring is pretty straight forward. I used a Haynes manual and traced the wires. If you know the basics of wiring diagrams and how to solder wires and use heat shrink you can do this. Just a warning make sure you disconnect the battery before you do any of this and double chk your wires before you cut or splice them. A lot of times color codes are not enough to go by.

To Summarize.
1. Being AT you will need to hack your harness and find the starter cut relay wiring. You need to gnd out the blu/wht wire either on the old trans connecter (the fat plug with a lot of wires going into the AT) or like I did go under the dash (more difficult than it sounds) and find the starter cut relay and gnd out the blu/wht wire that goes to the AT trans wiring. Another warning, doing this you car will start regardless of if you step on the clutch first, since AT cars have no clutch neutral safety switch. If you are ok with that fine. If not I suggest buying a switch an wiring it in. I have no safety switch. I just make sure to keep it out of gear when i park.

2. You need to wire up the VSS signal (blu/wht wire) from the new trans VSS to the ecu and instrument cluster. Without it you have no speedo, the odometer will not move forward and VTEC will not work. Additionally you will need to provide power to the blk/yel wire and gnd the blk wire on the VSS sensor.

3. You need to wire up the reverse switch to the reverse lights. There are two wires from the reverse switch. On my switch grn/blk goes to gnd and yel goes to the the wht wire for the AT reverse relay under the drvrs side of the dash.

If you got an MT Ecu, have a dealer reprogram it to match your key and you will have successfully converted.

619rcr · Jan 3, 2013

Gee whiz info for those of you who may swap to 5 Spd on an F23.
I also found later that my #1 O2 sensor wiring did not match up to the ecu anymore. My engine was an ULEV and since my new Ecu was LEV the pin locations were different. I had to chg a few wires and replace my O2 sensor to make it work.

To eliminate this problem, I suggest staying with same Emissions Ecu when you swap to 5spd.

619rcr · Jan 3, 2013

H22 Swap list summary on Pg2

Pics added today.

619rcr · Jan 3, 2013

5Spd swap complete, when I started my swap I was most concerned with the mounts. All The F23 mounts will line up fine with the exception of the driver side mount. Searching I found some interesting solutions. Some say drill another hole in the F bracket, some weld a new base. Some use 1 bolt to hold the F top bracket to the H base. But the Pieces are very sturdy metal & I have no welder... So I experimented with reusing my old mount and found that most of the holes line up fine if you reuse the F23 base (part under the timing cover) along with the top part of the F23 bracket. I will try to explain as best I can, since I didnt take pic of the finished base before my install.

Take the timing cover off the f23 and you will see the base bolts to the block with a few bolts. Unbolt it and place that next to the H22 base, (from under the timing cover) and you will notice a few holes line up fine. The main difference is the F23 base is shaped like the letter r & the lower right corner is reinforced with more metal.
The H22 base has the same r shape with another small section bolted to its right side with 2 more bolts. For a total of 5 bolts. But take the f23 base & grind off that reinforced section, 3 holes line up perfect to the H22. If I remember correct you will also need longer bolts. Bam you have the bracket and can reuse the upper section of the driver mount.
You will also have to trim the timing cover around the bracket a little. But this is easy compared to welding a custom mount or the risky use only 1 bolt to hold the 2 pieces together, which I have seen others use. I would rather have less bolts holding the base to the motor than 1 bolt holding the base to the top of the mount.
Pic of the bolt holes on the Block.