JDM h23 4th gen.

Hey guys. MAn, I'm so happy. I got this JDM 30k h23 for my 4th gen. It already had a USDM h23. I was wondering if anybody has a replacement guide on like a website or somethin to swap, cuz, well i'm used to old chevy's where it's pull the transmission and the mounts, intake, and exhaust and go. I realize it's not so easy on a honda, being a newer car that is. ALSO what do JDM motors have over USDM, cuz i know most of them don't pass emmisions.... there's gotta be somethin goin on there.

You have to remember Japan is very wasteful on resources and things liek that but the JDM motors are not de-tuned to meet the U.S. federal emission regulation laws and all that great BS. The ECU is burned differently, things may or may not be set at different heights such as cam lobes and what not, flat top vs dipped pistons. There are a ton of things that go along with the difference between US and JDM marketed vehicles. Why do you think J-spec motors are stronger than the cloned US motors ? US motors suck basically for the tuner market, JDM is the only way to go.

thanx. u really helped. I needed some info on that. Just by chance, do you know about how many horses a JDM h23 gets, cuz i've been searchin everywhere.... and i mean EVERYWHERE.

Go to Hmotorsonline.com and check out their motor mall i think it is. The h23 is in there

I got mine about a week ago from HMO and my friend helped me install it (he did mostly everything). Yeah there are some things that are different like the line for the fuel rail is on the opposite side. The EGR is different and needs another kind of connection. The distributor has the inner coil thing so you have to use your old one. Also the intake manifold has two extra vaccum lines, one behind the IM and one on the right hand side. Let me see... Oh and it doens't have a way to screw the black box (with vaccum lines connected to it) that is connected to the bottom of the IM. I haven't driven it yet because my clutch won't disengage all the way so I can't shift out of neutral when the car is on but when off I can. I don't mean to steal this thread but was wondering if it could be the release bearing gone bad.

I got mine about a week ago from HMO and my friend helped me install it (he did mostly everything). Yeah there are some things that are different like the line for the fuel rail is on the opposite side. The EGR is different and needs another kind of connection. The distributor has the inner coil thing so you have to use your old one. Also the intake manifold has two extra vaccum lines, one behind the IM and one on the right hand side. Let me see... Oh and it doens't have a way to screw the black box (with vaccum lines connected to it) that is connected to the bottom of the IM. I haven't driven it yet because my clutch won't disengage all the way so I can't shift out of neutral when the car is on but when off I can. I don't mean to steal this thread but was wondering if it could be the release bearing gone bad.


Did the clutch work before the swap ? If so if could be something simple like a adjustment for the clutch, you could have a air bubble in the clutch line, your master or slave could be shot, you could have a shot pilot or throw out bearing.

Easy way to eliminate master/slave cylinder being shot is look for clutch fluid puddles under the car or extremely glossy wet areas in those areas.

Easy way to eliminate the air bubble is pull off your inspection plate for the transmission ( underside ) and look where the slave cylinder pushes its rod against the clutch fork ( or more commonly known as a pitchfork ) and see if it moves, if it does - Good to go.

If neither of these, i'd be looking at some new bearings :D good luck man.

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And for you with the question about HP difference between J-spec and USDM -> You can usually on same vehicles just jspec or usdm version see roughly in the 20 - 30 HP difference range. Almost not enough to be worth it for the costs youd pay to get it.

The car drove fine before the swap (except for the very loud knocking the motor had). The slave cylinder was about a week old and the clutch kit was put on about 4 months before it happened. My friend said that it could have been that the bearing wouldn't work properly because it looked worn out.

Oh and I thought that there wasn't such a thing as a JDM H23? Many people told me it was a fake that its the f22 with the h23 head which is the same hp but less torque. Correct me if I'm wrong please.

The car drove fine before the swap (except for the very loud knocking the motor had). The slave cylinder was about a week old and the clutch kit was put on about 4 months before it happened. My friend said that it could have been that the bearing wouldn't work properly because it looked worn out.

Oh and I thought that there wasn't such a thing as a JDM H23? Many people told me it was a fake that its the f22 with the h23 head which is the same hp but less torque. Correct me if I'm wrong please.

Your not wrong.

I got mine about a week ago from HMO and my friend helped me install it (he did mostly everything). Yeah there are some things that are different like the line for the fuel rail is on the opposite side. The EGR is different and needs another kind of connection. The distributor has the inner coil thing so you have to use your old one. Also the intake manifold has two extra vaccum lines, one behind the IM and one on the right hand side. Let me see... Oh and it doens't have a way to screw the black box (with vaccum lines connected to it) that is connected to the bottom of the IM. I haven't driven it yet because my clutch won't disengage all the way so I can't shift out of neutral when the car is on but when off I can. I don't mean to steal this thread but was wondering if it could be the release bearing gone bad.

So if i used the usdm manifold and fuel injection system, i wouldn't have to worry about the 2 extra lines, right?

So if i used the usdm manifold and fuel injection system, i wouldn't have to worry about the 2 extra lines, right?

Right however, if you use a USDM head on a JDM block, the compression ratio for that black to that particular head/valve setup may not work very well but then again I see no reason why it wouldnt. The block only has like 2 sensors and an oil line so those Vacuums extra from a JDM head were probably some sort of emission by pass thing because japanese people really don't care all that much about emissions like the U.S. does.

I imagine if you use the block, us. head and keep the factory ECU, you shouldn't encounter any issues whatsoever.