(This is just for sake of conversation)
Ok, so we know the h23vtec (h23 + h22 head) makes decent power.
What we also know is that it's more fragile and less reliable. However, I do give respect to those very few people who have a reliable running h23vtec..
However, as a whole, how many people here believe that this is a doomed swap that ends up with blown motors and engine parts laying around?

I personally feel that though it is a decent hybrid, it is very dangerous to build one and very unreliable and realistic. All I see threads on is how this combination of motors results in blown parts and problems.

If it wasn't built by Honda... there was a reason for it. Meaning, the reason why there are so many problems with that combination is because I personally believe those two motor parts were not meant to be messed with like that.

Who else here shares this view/ Wants to elaborate?

Keep in mind none of this applies to the authentic h23vtec bluetop, but only to the h22 head and h23 block combination that people call h23 vtec

 

From what I have read there is nothing wrong with doing a H23 w/ H22 Cly. Head build... IF it is built correctly..

And building correctly does not included having an H23 block, taking off the Cly. Head and putting on an H22 Cly Head, Adding VTec Computer, And wiring, and running the motor.

Yes, it will work... And yes this is what will blow the motor. It can't be done like that and expect it to stay alive.

My .02¢!

 

personaly i say it can be done and should be if you can do the correct setup. the main problem with alot of people running the h23vtecs is that they do only the most basic things for the swap, dont get a VAFC and have vtec set at 5500rpm. at that rpm, with a h23 transmission you have to rev the engine almost to 8500 to keep Vtec engaged. that plays hell on both the h22 and h23 bottom ends.

everyone says that it is because of the h23 have poor main or rod bearings. but the h22 and h23 use the same rod and main bearings. so if they fail in that area wouldnt be the tranny that would make the difference?

 

I finished my H23vtec this summer, been driving it for about 3 months now (~7000 miles) and the only probelm I had was the oil pressure sensor failing - which has nothing to do with the conversion. I'm also running w/out a balance shaft belt. If anything blows up, I'll be sure to let you know.

 

well i dont know much about this swap. but honda did make an h23a. and it was vtec with a blue valve cover. it only came on the jdm accord sport wagon. check it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelude964 &raquo;</TD></TR><TR><TD CLASS="quote">Keep in mind none of this applies to the authentic h23vtec bluetop, but only to the h22 head and h23 block combination that people call h23 vtec</TD></TR></TABLE>

 

Yeah, you can do it. Stay under the stock H23 rev limits most of the time and you'll be fine. Only rev the hell out it when you really need to.

 

It's only good if it's built right.

When you start monkeying with the engineering from the factory, you better damn well take into account the things that will be changed when you change one part in a system! This applies to any hybrid motor.....

Each motor has strengths and weaknesses; if you address the weaknesses, it will be a strong reliable motor.

 

h23/vtec

you'll like how the motor feels throught the whole band....keep the revs to 7,200 rpms max and it should last...

 

What would be a safe rpm to rev too: H23vtec v. G23vtec? I'm just asking because in my mind after thinking about it some, if they both rev to the same point, wouldnt the extra stroke of the G be better? Just a thought/question, not suggesting one way or the other.

 

g23/vtec would be more potent of course....i would rev it to about the same of the h23

 

Okay, how does everyone here feel about the block differences between h23 and h22? There's a lot of talk about the h22 being designed better, if this is true, how can one modify an h23 block to better handle the vtec forced upon it by the h22 head?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tarheelsoldier &raquo;</TD></TR><TR><TD CLASS="quote">.... at that rpm, with a h23 transmission you have to rev the engine almost to 8500 to keep Vtec engaged....</TD></TR></TABLE>

Not true at all. I've had an H22 in my Accord with an H23 tranny for 2 years and you do not have to rev to 8500 or close to it to stay in VTEC.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vinuneuro &raquo;</TD></TR><TR><TD CLASS="quote"> What would be a safe rpm to rev too: H23vtec v. G23vtec? I'm just asking because in my mind after thinking about it some, if they both rev to the same point, wouldnt the extra stroke of the G be better? Just a thought/question, not suggesting one way or the other.</TD></TR></TABLE>

Well it depends on youre setup. If you're just using a stock F23A shortblock, I would be really cautious about revving it past 6500 rpm, the stock F23A redline. If you lighten and balance the rotating assembly (which is what I had done) you can go higher. I'm going this route for the midrange torque, and not having to rev the hell out of it to go fast.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cb7-R &raquo;</TD></TR><TR><TD CLASS="quote">

Not true at all. I've had an H22 in my Accord with an H23 tranny for 2 years and you do not have to rev to 8500 or close to it to stay in VTEC.</TD></TR></TABLE>

i shift at 7200 in my h23/vtec with h23 trans with vtec at 4500 and i dont fall out of vtec shifting from any gear to another...h23 trans

 

Sam1am26's proposed G23VTEC thread
https://honda-tech.com/zerothread?id=1323703

My post in regards to high Rev-ing G-series:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">If you are going to use custom forged pistons an alternative to crankwork and B-series rods would be to spend the extra money on lighter pistons and wrist pins. The following shows how the difference in piston weight results as a higher rpm for the same piston deceleration force.

419g ...... 369g ....... 344g ..... 319g
OEM g ... -50g ....... -75g ..... -100g
6500 ...... 6925 ....... 7175..... 7450

At the stock F23A5 at redline (6500rpm) the piston experiences ~3082Gs of deceleration at TDC. The F23 piston/pin/rings weigh 419 grams. That translates to 1,291 kilograms of force that the rod bolts experience. 419 grams is pretty heavy for a piston. Basically, if you can drop 100g off the piston weight then you can effectively rev to 7500rpm on stock rods with a high degree of reliability as the rod bolts experience the same loads as the stock engine at the original red line.

The only wear that I might consider is that the OEM rod bearings are designed to handle ~140hp at the crank and if you build the engine you can get well over 240 at the crank. So the narrow rod bearings might wear prematurely if you incessantly beat on them.

Short story: lighter pistons = higher revs reliably for less money.</TD></TR></TABLE>

If you build it right then Hybrids are fine just do the appropriate research and build according to the application.

Pirate

 

stroke is money

use it...

there is a guide on here to building a reliable h23 vtec....follow it and it wont fail you unless you fail it....

 

I read all your posts and see a lot of negativity towards the swap. I guess I am in the minority then. I did have my growing pains with the setup but this is how I got my setup to produce the big numbers.

I originally went to Golden Eagle for an H22 sleeved block but they happen to have an H23 closed deck block sitting in the shop. I went the full monty and did the O ringing too. When I finally got it, the assembly and machine work was done surprisingly top notch.

When my turbo hatch was completed a year later and I went down the second time down the track the oil pump failed and I took out a rod, some valves and some bearings.

We later found out that the clearances were too tight for racing and we decided to loosen the motor and redo the oil pump gearing clearances. My first pro drive oil pump was shattered in several pieces so we knew that this was the cause of the failure.

As for the H23 working on the H22 VTEC head that has been the least of our problems. The VTEC has worked flawlessly and the car is making over 700 whp.
Two years later, the same motor is still in my EG hatch and the compression has checked out perfectly with only a 5% leakdown. After running over 50 passes on the motor, 100dyno runs etc., the motor has exceeded all expectations.

So yes, when they are built right, they last. It is very important to clay the head and get the setup to line up correctly. It takes detail and patience to be different.
Since I ran the most of the NOPI race season I have inspired many racers to take another look at the H motor in turbo form. Lance Ho Lung inspired me to go this way from the beginning and I have no regrets.

As for the transmissions....... they are just as durable as the B trannies. I don't know what the fuss is all about. Except for my recent turbo rebuild, I did finally have a gear failure but it was mostly due to the countless burn outs to warm the tires. I have a stronger box going in this time, but in the meantime I have been using an H23 non VTEC $350.00 junkyard box and qualified #1 at the last race at MIR with a 10.28@144mph on a bad smoking turbo. If your cables are not binding and you have them secured properly you should have no issues with shifting.

As for redline.... I run stock cams and go up to 9000rpm. I have good components in my setup so your results may vary depending on your setup. I just wanted to share a positive experience with all of you so you don't think this setup is just gloom and doom.

my 2 cents
Michael Ko


Modified by cul8tr at 4:32 PM 10/8/2005

 

H23 VTEC's on H23 tranny's are not that bad. If you tune it down (like you're SUPPOSED to ) and set VTEC lower, you can easily stay in VTEC if you rev high.

H23 blocks are the exact same as the H22 blocks.

IIRC, from my math on the H23 VTEC, H22, and G23 VTEC, the H23 VTEC is fine for rev'ing to 7600 and the G23 VTEC is good up to a little over 7k. This is all based purely on sideloading and piston speed.

 

Time and again, bearing wear has proven to be the problem (Satan's h23vtec, sam's, etc). I'd imagine a G motor having the same, if not worse problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vinuneuro &raquo;</TD></TR><TR><TD CLASS="quote"> Time and again, bearing wear has proven to be the problem (Satan's h23vtec, sam's, etc). I'd imagine a G motor having the same, if not worse problem.</TD></TR></TABLE>

Well the journal's are the same size on the H22A1 and H23, so the speed is not a problem.

The only two examples that you listed had poorly prepared cranks. Satan's was lightened and knife-edged (and his crank cracked in half), and Sam's was a completely stock H23 bottom end, no balancing or preparation. I told him and he's admitted that he should have balanced it beforehand.

It's not the bearings....

 

That makes me feel better. What are you revving yours too? Bottom end specs?

 

My bearings were just ever so slightly above the mid spec from the manual. Entire rotating assembly was zero-balanced. Stock H23 rods, stock USDM H22 pistons, Clevite bearings, H23 crank, H23 block. Rev to H22's fuel cut (7600 RPM) fairly often

I have the balance sheet from my machinist showing how poorly the H23 crank was balanced from the factory, if only I could find it....

 

Slightly above mid-spec after how many miles?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudeyKrus &raquo;</TD></TR><TR><TD CLASS="quote">It's not the bearings....</TD></TR></TABLE>

That makes me feel better too. Although on the G23's the rod bearings are very thin.