H23vtecEF

I am in the process of building my h23vtec civic. my mounts should be in wed. and it should be in the car next weekend. but i have searched and cant seem to find what header to use. I didnt know if i could use one from a h22, and if there was a difference between a h22a1 and a h22a4. this motor is hard to find information about and any help would be appreciated. thanx

Kronn 98SH

H22 Tri-Y

jlude90

h22 and h23 blocks are identical, so you just do it based off of the head, so any h22 header will work

well, bolt-in, any h22 civic header, but if you want to do some work, any h22 header will do

InvaderTrax

4th and 5th gen H22 headers will be different as far as how far back the piping goes, but it's not gonna bolt to a factory Civic exhaust anyway so pick whichever you can get cheaper

MLBZ521

iTrader: (6)

The H23 VTEC uses an H22 Cylinder Head.

All upper portions of H22 Headers will be the same, it's the down pipe that will be different.

jlude90

no it will not. like i said, H22 and H23 blocks are identical they're even the same block casting. nothing is different about the block, for all intents and purposes they ground off the H22 on the block and stamped H23 on it, its the exact same, nothing is different on a h22 or an h23vtec header

MLBZ521

iTrader: (6)

Who are you talking to and what about??

What does the blocks being supposedly identical have to do with the Header?

jlude90

why would the downpipe be different from and H22 to and H23VTEC?

MLBZ521

iTrader: (6)

Because they're from two completely different cars??

jlude90

a 4th gen and a 5th gen header would be different, but h22 vs h23vtec would be the same, and like i said, any prelude header would have to be modified, but any H22 header for a civic would be fine

MLBZ521

iTrader: (6)

Um.. The H23 VTEC is from an Accord.. Not a Prelude..
I think we're talking about two different things..

Your talking about a H22A/H23A1 Hybrid and I'm talking about the JDM H23A VTEC Engine..

Kronn 98SH

I think the OP has the H22 head on the H23 block. In which case, I still say H22 Tri-Y Hytech replica.

MLBZ521

iTrader: (6)

Well, I was going off what the OP stated:

The Hybrids aren't hard to find info on, where as the JDM H23A VTECs are..

But I don't know why you're saying the H22 Tri-Y Header in particular.. The are many others that will work..

Kronn 98SH

I'm guessing based on what the OP said, also.

I recommend the Tri-Y because it's the best bang for your buck. I know others will work, but why buy anything else?

MLBZ521

iTrader: (6)

I saw your dyno of it and maybe another one.. But until there are more and/or compared to similar setups with other headers, I'm not sold that it's the best by any means.

I also would rather pay someone to custom make a header for my application than an off the shelf Header.

Kronn 98SH

I said "best bang for the buck". Obviously a custom header would out-perform it, but that will also cost 2-3 times more.

jlude90

holy hell

an H22, an H23 with an H22 head (called an H23VTEC) not an H23A, but if that H23A has an H22 head on it, then they will ALL use the same header

MLBZ521

iTrader: (6)

Yes, any H22 Header will bolt to the Cylinder Head, but depending on the vehicle they were designed for, the downpipe section will not be the same length.

technishane

I know I'm posting long after this thread was started but just in case anyone reads this looking for info I am currently putting the JDM H23A DOHC VTEC in my 2000 Prelude. The factory headers are identical. The stock header & down pipe combination from my Prelude is not going to work because the oil pan is different. The H22 has an aluminum pan. The H23 VTEC has a steel pan. The down pipe rests firmly touching the oil pan for a solid 3 inches which will put lots of extra heat in my oil & cause all sorts of havoc. I could switch oil pans but I've heard that you have to do some grinding in order to make them fit.

My guess is that since the Prelude sits so much lower than the Accord wagon Honda decided to run a shorter bend on the down pipe and had to put a deeper cut-out under the oil pan to accommodate.

I'm on here now trying to figure out what will work best, however it seems no one is mentioning this specific issue and no one knows the measurements of these parts.

I found out the hard way that the 4th generation Prelude H23 non VTEC header has a different bolt pattern.