Here is some useful info for doing any motor swap but the info posted below is mostly about the H22A swap into an Accord.

Enjoy.

 

First things first. Buy a Helms manual for both the engine you have and the car it is going into and get acquainted with them. THIS IS WRITTEN ASSUMING YOU HAVE A HELMS AS A REFERENCE. Try to get all the parts you will need beforehand, this can be a pain in the arse if you don't know what you will need because of the lack of consistent info on this swap-or blantant misinformation from kids who had a shop do it, but like to speculate and give advice as to the hows and whys without knowing what they are talking about. Hopefully this little piece will help.
If you can, INSPECT THE MOTOR BEFORE YOU BUY! Find out the results of a compression test if you can, I think some crate motors come with paperwork with results. All I did was pull the plugs and valvecover to see the piston tops and general condition of the head, and turned the crank with a wrench to make sure it wasn't seized, and verify that the valvetrain moved smoothly. Give the motor a visual "once over", to see what you might be replacing/fixing.
*** ENGINE PREP:
Depending on the condition and mileage of the motor you have, you may want to replace more or less. Keep in mind that it is all easier with the motor out. The JDM motor we purchased was a bit weathered, there was some water in the head and a bit of rust on the cams. I pulled the head apart, save for the valves and cleaned the ****e out of everything. The oil pan was also dented. Since the mounts, hoses and axles are all cut to get the motor out in what I am sure is record time-they are useless. Here is what we had to replace, to give you an idea of what you are getting in to.
*** PARTS LIST:
$plug wires and plugs
$valve cover gasket
$plug grommets
$valve cover bolt grommets
$cam seals
$oil pan and gasket
$H22 drivers side motor mount
$H22 throttle cable and bracket
$H22 PS line
$IAT sensor
$Clutch (we used an ACT Xtreme plate with heavy duty street disk)
$Timing belt (beware, replacing the timing belt on the H22 is kind of a biatch. There is a special tool to compress the tensioner, which is unnecessarily complex if you ask me. It can be done without it, just be creative and PATIENT!)
$PS, AC, and Alternator belt (these may be custom lengths depending on what pumps and pullies you use.)
$H22 MAP sensor, brackets, vaccum hose and evap canister. (You could probably stick with the Accord canister as well.
$Crank pully (the one on the motor was chipped to hell.)

*** PARTS COMPATIBILITY DETAILS:
Mounts: This motor basically bolts in using the all the Accord mounts except for the drivers side mount. A Prelude mount must be used, and the metal bushing that holds the bolt mounting it to the frame must be shaved down slightly to fit between the brackets on the frame, you will see when you do it.
Axles: Use the stock Accord axles, and intermediate shaft.
PS Line: You will need the PS line from both the Accord and the Prelude, and have the Accord lower half (that connects to the rack) spliced with the Prelude upper half (that connects to the PS pump.) Fitting shops can do this, it costs around $60. Make sure you get it long enough.
PS pump and bracket: Prelude pump and bracket
A/C compressor and bracket: Accord compressor, with either bracket
Alternator and bracket: Accord alternator, and Prelude bracket *NOTE: Other combinations may work with the accessories, this is just what we did. Keep in mind that belt lengths will depend on what you use.
Belts: Depending on which accessory pumps you use (Prelude or Accord) the belts may be different length. For example the pully on the Prelude's A/C compressor is a lot smaller than the one on the Accord. Basically, just get your stuff mounted up and measure the length of the needed belt, and take yourself to NAPA. We ended up using the stock length Prelude PS belt, and a 43" belt for the Accord A/C compressor and Alternator on the Prelude.
Hoses: Use the upper and lower radiator hoses off the Prelude, as well as the drivers side heater hose, that goes to the back of the block. You may also need to pick up some vaccum hose, as some of the solenoids, valves etc. are going to be in different places. Consult the vaccum hose diagram in the Prelude manual for more details here, it's pretty self explanitory.
MAP Sensor: You will need the MAP sensor off a Prelude, as the Accord MAP is mounted on the throttle body, but the Prelude has it mounted on the firewall. May as well pick up the bracket with the 3 hard lines for the vaccum hoses that also attaches to the firewall (See vacuum hose diagram.) We also got the Prelude EVAP canister, as it has 3 vaccum lines and the Accord has 2, just to avoid confusion. If you don't care about money, get it from Honda, if you do-go to a junk yard.
Exhaust: The combination of the Prelude header and the Accord cat/exhaust did not work. The Accord cat is too long. You have options of what you can do. We bought an aftermarket header and had a muffler shop cut the exhaust and weld everything up. You can have the excess length taken out of the header or out of the exhaust, it's your call. I have been told that a Prelude cat is shorter, but someone else will have to look into that.
Shift linkage and clutch linkage: Accord
Throttle cable: Use the Prelude throttle cable and bracket. Someone with a small bit of creativity could get cruise to work, by fashioning a bracket to hold both cables properly and shortening the cruise cable and attaching it to the throttle pulley. We didn't do this. *NOTE: The Accord throttle cable attaches to the pedal differently than the Prelude. There is a gap that the cable can come off using the Prelude cable, just use your head and secure it in place. There is more than one way to do this, you will see.
Harness and ECU: Use the Accord harness, and ECU for the H22 (obviously.) The harness must be modified (no simple task, see wiring section.)

 

*** WIRING:
Now to clear things up, many people emailed me saying to use the Accord harness and just add the VTEC pressure, VTEC solenoid, Knock Sensor, and Intake Air Bypass wires and you are set. Similar to a B series EG swap, easy right? Well, the truth is actually much, much darker...
First of all, about half of the wires for the sensors have to be relocated/lengthened. This is difficult going into the whole thing blind, and you will spend a significant amount of time cross referencing wiring diagrams in you Helms. I will spare you that pain. Also avoid "mickey-mousing" it, buy some flex tube and tape so you can give the illusion that the wiring was not d; it, buy one by a drunken blind man.
Also, and I can't stress this enough, CHECK YOUR GROUNDS. They are the cause and solution to all of lifes problems!
* Wires to add:
VTEC Solenoid: Grn/Yel on Prelude harness > Pin A4 on ECU // SENSOR LOCATION: Near distributor
VTEC Pressure Switch: Lt Blu on Prelude harness > Pin D6 on ECU // SENSOR LOCATION: Near distributor
Blk/Red > Ground
IAB: Pink on Prelude harness > Pin A17 on ECU // SENSOR LOCATION: Drivers side of intake manifold
Blk/Yel > 12V
Knock Sensor: Red/Blu on Prelude harness > Pin D3 on ECU // SENSOR LOCATION: Middle back of block
* Sensors to lengthen:
(NOTE: Consult the helms for the location of sensors, and color code of the wires on your harness.)Colors below are for the Accord LX harness.
IAT (GRN/BLU-RED/YEL): Too short, needs to reach drivers side of intake manifold.
MAP (YEL/WHT-GRN/WHT-WHT/YEL): Too short, needs to reach wherever on the firewall you mount the MAP sensor.
EGR Lift solenoid (GRN/BLU-WHT/BLK-YEL/BLU): Too short, needs to reach passengers side of intake manifold.
H02s (GRN/BLU-WHT/RED-ORN/BLK-YEL/BLK): Too short, needs to be run to O2 sensor, near oil filter.
IAC valve (BLK/BLU-YEL/BLK): Too short, needs to reach top of intake runners, in the middle.
ECT switch A: This will need to be extended to the thermostat housing on the passengers side of the back of the head. The ECT sensor and ECT sending unit fit fine (under the distributor.)
*NOTE: There is no ECT switch B on the JDM H22, just spare back the connector.
Alternator: The power wire on the alternator needs to be lengthened about 2". We just cut the one off the Prelude harness, and attached it to the Accord harot;. ness with a large enough splice.
*NOTE: SWITCH WIRES A6 (EGR solenoid) and A11 (H02S heater) at the ECU
When you think you have everything wired up correctly, plug in the brick and turn the key. Have a multimeter ready to troublshoot if you throw codes. Remember, some of the sensors may be bad so don't run yourself into a wall thinking you wired wrong. (Although you may have.)
*** HOW TO:
Remove the stock motor, follow the steps in the Helms if you haven't done this before. I will assume you have a hoist. Take care removing the axles, pull them straight out of the tranny to avoid damaging the seal. It makes life easier if you remove the radiator also, as the motor/tranny must be cocked to get the tranny past the passengers side mount. Having the radiator out just gives you more mobility, and it takes about 10 seconds to remove. While you are at it you may as well remove the subframe that the trailing radius rods and front mount connect to (about 5 seconds) for even more space. Double check that everything is disconnected and hoist the motor out, this is easier with two people one pivoting the motor and watching for clearance in the back, and the other running the hoist.
Have the H22 ready to go (wiring especially) before you put it in. Drop the sucker in the opposite of how you took the F22 out, lining up the mounts etc. The H22 seems to lean back in the engine compartment, don't panic-it's normal. I am not going into too much detail here, you know what you are doing if you bought the Helms. Grind down the Prelude drivers mount, like I mentioned earlier. (Just enough to get the metal bushing to fit between the frame brackets.)
Mount your map sensor, vaccum hard lines, and EVAP canister on the firewall and consult the vaccum hose diagram on how everything interconnects. You will have two hoses to cap off on the tranny, where the power steering speed sensor connects (passengers side). Usually these would go to the Prelude rack, but since there is no matching connection on the Accord rack, they are useless.
Put everything back together, and run your additional wires to the ECU. You can get all tech, and actually get the ecu pins from Honda but it works just as well to strip the wires back (I used 18 ga. BTW) and push it into the proper place on the clip. This method isn't as cool, but has never given me any problems. DOUBLE CHECK ALL YOUR WIRING AND HOSES! Hook up the Prelude throttle cable, as well as your intake and header of choice, noticing that your car is going to be extremely loud driving it to the muffler shop. Finish putting everything back together, AGAIN I am assuming you have a helms so you know the steps!
Make sure you have all the fluids replaced, and everything torqued. Finish putting everything back in, and clean that dirty little motor. Stand back and adjust yourself, so on lookers think you had it all locked down from the beginning.

 

I ALSO HAVE A WIREING DIAGRAM FOR RUNNING THE EXTRA WIRES TO THE ECU HARNESS.

If you would liek a copy of this diagram feel free to PM me and I will e-mail you the file. Or you can try to catch me on AIM and I'll send you the file that way.

 

MODS, Can we make this a sticky????????

 

you can use the accord map sensor. you take it off the TB and stick a vac line on the nipple.

as for the ect b that the h22 dont have.....

sometimes the radiator fan wont come on if you jus dont hook it up. get the upper bottle neck off the f22 and stick it on the h22, they are the same thing.

for the exhaust the easiest thing i found to do is to get a prelude cat and usdm header and have a section on the exhaust cut out to make it fit. the flex pipe the h22 header's have is far better than the gay spring bolts the accord has. if you use a jdm header the collector on it is bigger and you will prolly have to have it cut and welded to the exhaust

PS line..... you can use a 97 prelude ps line instead of making a custom line