H23 Vtec Conversion

Im thinking about doing a H23 vtec conversion in my prelude, but i have a few questions. Are the pistons in the Si model and Vtec model the same, like will they be able to withstand the same amount of abuse. Also, if i put the oil squirters on the block, will that get in the way of the longer stroked H22 block?

From what I've heard the frankenstein engine your describing is a bad investment the compression will screw you unless you get new pistons etc.

90% of the people who's done it claims it's unreliable. 10% of those who's done it says it is. The h23a bottom end can't take what the h22a head is capable of.

well say i was put new pistons in, just pistons, would that work or do u think id need new rods. I know the crank will be able to hold it.

well say i was put new pistons in, just pistons, would that work or do u think id need new rods. I know the crank will be able to hold it.

You can't JUST put new pistons in. The cylindar walls consist of a sleeve called FRM, or "fiber-reinforced metal". Basically, this reduces the thickness of the sleeves, without sacrificing friction, so the engines can have a larger bore. The downfall of this is that they only work with honda factory pistons. Therefore, if you are upgrading pistons, it'd be a good idea to resleeve your block to avoid catastrophic engine failure due to your piston hitting your cylinder wall when the piston expands faster as it heats up.

Resleeving costs upwards of a grand, plus the price of new pistons. Have fun!

Ya but isn't the H22 also made of this same material? Cuz the bores are the same on each engine. Wouldnt the pistons be hitting the H22 also then when they expand

Ya but isn't the H22 also made of this same material? Cuz the bores are the same on each engine. Wouldnt the pistons be hitting the H22 also then when they expand


EDIT: I think I know what you mean. The factory honda pistons are able to handle the FRM.. I think they do this by a thin iron coat around the piston.

Like okay, what i just really want to know is, what kinda differences in the bottom end of the H23 and H22 is there, like strength wise. I know theres a lesser compression cuz its got a longer stroke and maybe dif size pistons, not sure.

More Tourqe Thats What Every One Tells Me 156 Lbs/ft Of Tourqe

I know the H22 crankshaft is better counter balanced than the H23..

On a side note, i just wanna say props to Prelude97 cuz of his signature, my friend is obsessed w/ his ford probe and we have been argueing about it all day then me and him are reading ur post and i just cracked up at the signature.
Anyways, i didn't know they had different crankshafts in them. From this book that im reading on Honda engines, the blocks on both engines should be the same, strength wise. I know the open deck design is gonna be bad either way. I plan on upgrading the pistons and eventually sleeving the block. I want the prelude vtec but the Si was so much easier to find. I plan on turbo charging the car, money isn't that much of an issue.

4th gen blocks are closed deck.

You could always pin your open deck block anyway..

i got the h22 head on my h23 what is my red line becuse the h23 red line at 6.5 and the h22 is at 7.5 and i put and the pro. chip

Your redline is determined by whatever ECU you have plugged in. I have no idea what this "pro. chip" is, but that may be the final determinant to your rev limiter.

I think he means reprogramed chip

"The reason why i was not getting an extended redline was because there is an "oil control orifice" on the H23 block that needs to be removed. I removed this "plug" and reassembled the head. Sure enough, my redline goes to almost 8000 RPM

I figure what you said AcesHigh about the readline was true, which is correct? GWInquisitor14, can you give me some info on this book you are reading? I like to have all the honda info i can, and i'de like a copy of this.

The more i read about this H23 vtec on this forum, the more it turns me against it.

Yeah its called High Performance Honda Builder's Handbook, volume 1. I think there is a volume 2, but its more about suspension and NOS. You can get it at any local barnes and nobles or pretty much any book store, just check out their automotive section. I bet you will find more than just that book on tuning Hondas, cuz i did. The one i bought sparked me the most into buying it.