JDMFLCL

I have a few questions about hte G23 Vtec. I'm looking at the following speculative build

I/H/E (2.5" catless)
F23 Block
H22a Head that is Pnped/valvetrained/cammed/Coolant ports professionally blocked off/ARP Head Studs
F23 Rods (Maybe forged ones?)
F23 Crank
F23 Water Pump with H23 internals
New K20A2 Pistons
H2B adapter to a ITR Transmission
All of this in a DC2

Here are my questions
1.) What motormounts do you guys recommend
2.) What EMS?
3.) Any of the above parts look out of place?

I'm looking for a reliable nice high revving motor. The G23 seems to have hit the spot. The Integra I'm going to pick up will most likely be a LS, so keep that in mind! I'm looking for 200whp @ altitude

flyrod

Stroker builds are not really the best for high revving.

gstrudler

Yep, you better be looking at Crower rods (they are the only ones producing an f23 rod that I remember) and some lightweight pistons if you want to rev it out at all. The stock redline for the f23 I think is in the neighborhood of 6500rpm.

Bluetop

dont do a g23 with the f block, use a 98+ block and just drop in the crank and rods from the f. then you will have 87mm bore and 97 mm stroke for a real 2.305 liter.
your better off doing a h23 vtec or buyng a 98 spec h23a blue top for top end purposes.
the blue top h23a has 205 hp from the factory and way more midrange than 2.2.
the 97 mm f crank is only good for tourqe.

dont buy rods because they are heavier than stock, just lighten the piston by fly cutting .025 of the top of h22 or h23 pistons, which you have to do anyways so that they stay flush with the deck.

plus k20a2 pin offset is opposite of the h piston which means your piston will load up at the wrong degree completely opposite of what it was made to do.

not to mention that you will still have less displacement than an h23 and if you over bore the f block you max out the overbore on that block and weaken the sleeves, it will work but for how long.

i have built a h23a blue top with f23 crank and rods, fly cut h23a pistons, crower 2 cams that are basically type r cams with bigger primaries. im tunning this week and will post the dyno, it should put down 185 wheel tourqe at least.

Bluetop

oh yeah horsepower is like a cash and tourqe is like gold

JDMFLCL

So you'd get a bluetop H head, overbored F23 block, 98+ F series internals and forged pistons?

I'm downgrading immensely in power and torque from my current car
Can I get a preferred internals list?

which 98+ block? 98+ H series block/heads with F23 crank+rods+k20 pistons?
I'd like to run this on Catpiss 91 octane, although E-85 is an option if i go with a switchable EMS.

7000ish rpm is what I am looking for, which compared to my current EJ20G which just dies @ 5500 rpm is good enough for me.

gstrudler

You can't run k-series pistons in the h-block, you can only run the h-series pistons or mahle gold's because of the frm lining. When you said 'high revving' I misunderstood your intentions; the reason I recommended a rod upgrade is that the stock f23 rods have puny rod bolts and there are no upgrade options right now (although ARP is supposed to have them in their catalog in roughly a year or so). However, if you are only wanting to hit 7k, the stock rods should be fine.

JDMFLCL

After having done more research, it seems like indeed the easiest would be something along the following lines for my goals (220whp @ sea level). What pistons would you recommend if I went with forged rods?

98+ H22 block
F23 Crank
Forged rods of some variety
H22 pistons
H22 head
ARP head studs
Cams
I/H/E

something like that? This would be going into a DC2 w/ a H2B

jusabill

i also want to do this build but sourcing parts is a pain in the a** thanks to the h-t fam for all your help !!!!

flyrod

If you're looking for 220whp then there are a few ways to get there. Pirate's build got there with relatively cheap parts; the forged pistons were probably the most expensive item. Also the stroker builds using the H23 and F23 cranks will get you more torque, which is fun around town. You could also build a regular H22 with some good parts and get 220whp. Check out the H22 dyno thread to get an idea of the setups people are running to get 220. Also fyi, the F23 rods are fairly unique, so "forged rods" basically means $$ that could possibly be better spent elsewhere. Another issue with the F23 crank and H22 pistons is that the pistons will stick out of the block a bit. Check out some of the hybrid threads listed in the FAQ in the prelude forum. Good luck.

jusabill

anybody know the differences between usdm head and jdm head both h22( 97 to 01)

hYbrid_snIper

I have a similar build I just started,
H23 Vtec head
springs/ retainers / valves
F22A1 block
ceramic pistons / ceramic rods
looking to raise the compression above the 9:1 (near-er to 11:1) the frankienstien's seem to make from what I've looked up.
custom, turbo/supercharger set up

does anyone have any insight into estimated or known forced induction dyno charts for any G23 vtec builds, im looking to start ball parking my RPM and power numbers to finish the planning around the fuel/brake/suspension/electronic set ups

thanks in advance

honda_12V

iTrader: (2)

Hello,

I am also preparing a force induced G23 motor.

The block is a 98 Odessy JDM F23 block, bore 86mm. like everyone says you can rebore the block to 87 and use H22 pistons, but IMO that will weaken the engine for a force induced application.

From what i understand and after speaking with various people who have done G23 builds and F23 built blocks, included Pirate, using K20 pistons is not a huge issue. They have used it and held on to everything just all right. You will have to rotate the pistons due to the diffierent pattern of Intake and exhaust valves on the K20 head.

Further, as far as rods are concerned F23 and K20 rods have the same specs only difference is the length from 141mm (F23) and 139mm (K20). The difference is of 1.4%, IMO from what read research done on chevy engines if the difference is below 2% there is no considerable change, between 2-5% a change will be experienced. Over 5% has adverse effects on rings lands.

Out of what the experts have to say, F23 rods are the way to go crower make F23 rods forged turbo tuff, a cheaper option is Race Rods offered by Raceeng.com , or I am thinking of going for K20 rods out of a crazy fancy. I know the pistons will sit 2mm further inside the block... like i said crazy fancy.

I am hoping to use CP flat top pistons with K20 manley rods, get the compression around 9.07:1 and boost the setup with 6262 precision turbo a/r 0.82 hopfully around 9-12 PSI, cant find strong evidence the block will hold more than that. F23 is a open deck block.

Regarding the EMU, i hope to use a ecu from a h22a7 (EuroR) for the break in period running normally aspired and then move to a aem series 2 box. I understand Hasport H mounts should do the job, as F and H use the same mounts. Will be using a U2Q7 LSD box.

My list of internals would be as follows:
H22a4 head Stock JDM (or with crower turbo cams if i can afford it)
F23 JDM 98 block PEA
H22 cosmetic gasket 0.30
H22 ARP head and main bolts
K20 pistons CP flat
K20 Manley rods
F23 ACL bearings.

My power goal is around 400hp mark.

Would like to have your opinion on my work / plan / research.

Regards

honda_12V

iTrader: (2)

Hello,

For the high rev issue, If you are using K20 pistons then there is a issue of mean piston speed and maximum piston acceleration.

According to those calculation the piston speed on a K20 red line at 8000rpm the mean speed is 1903 fps and maximum acceleration is 129545 FPS (power 2) the same on a G23 red line 8000rpm, mean is 2147 fps and max is 150693 fps (power 2).

IMO forged pistons should be able to hold the extra speed but it would be advisable to keep the red line around 7400rpm as then the mean is 1986 fps and max is 128937 fps (power 2). Provided your valve train is ready to for this rpm, normally H22 head can take upto 8000rpm on stock setup.

My 2 cents.

Regards

hYbrid_snIper

thanks for the reply, what equation could i use to look up pistons speeds?
travel length (times) RPM basically?
would high compression pistons and a shorter stroke help keep the speed down and increase RPM limit, assuming head was build and rods and pistons were installed?
im looking for a compound boost set up for time attack and want to stretch that turbo once it replaced the supercharger..

thanks

honda_12V

iTrader: (2)

Hello,

Normally i use the zeal works compression calculator:

http://www.zealautowerks.com/hfseries.html

Though, IMO i would use F23 rods, if you really want to rev the engine over 8000rpm. Even though they dont effect the speed on pistons but having the piston sit perfectly in its bore would definitely be of advantage if you really want to rev that high.

Further, you can use any high comp pistons cause the clearance in the H22 head is 53.80, what compression ratio you looking for? But you mentioned supercharger and compound boost, that means you wont really be building a high compression engine, you need to build a low static compression engine around 8.8:1 or 9 and then boost the guts out of it. I really dont know how much boost a F23 block can take but for daily use around 15:1 should be ok (B20 turbo run that all the time) but for race on higher octane gas or meth am sure it can hold more.

Have you looked into water meth systems to get more power in the same setup instead of reving the guts out it. And choice of turbo would be key if you thinking of boosting it.

From what i have read the F23 block can take alot of abuse even being a open deck block and not closed deck. IMO stretching the redline will not definitely effect the power band of the engine, once you have peaked your power curve, power delivery will only go down and not up.

IMO, if you can have a really good race port and polish, on a DOHC head you will flatten the torgue curve which would be beneficial for your application.

Hope i helped

Regards

hYbrid_snIper

Im using an F22A1 block and H23 Vtec head....
I would imagine however the deck heights are similar in h22 and h23.(calculator says 50 for h23) I want to make sure I can safely rev as high as i need, im ceramic coating the pistons and rods to bring the temp on them down and micro polishing the intake and exhaust/race port matching
currently I think, 10:1 would be good to start at, since thats not a lot higher than the 9:1 these builds seem to yield.
that calculator and its features are awesome! thanks alot it will help a ton.
the theory being for the high compression pistons is that you can turn the boost down, increase response and hit full boost sooner, i know with the supercharger lag should be nill, but since im not sponsored the secondary effect is that in theory the wear should be a little lower since the pistons are not being driven as hard, even though the compression goes up. from what i have seen in the new high HP builds shops are using 12:1 pistons and ~40psi of boost for drag cars now, instead of choppings the rods and low comp pistons, according to the shops(speedfactory, most recently, with the fastest civic in the u.s.), the tunes they run and the quality of the parts make high compression pistons and boost feasible now.
the block has a decent turbo on it already, so im planning on staying with that, T4, twin scroll, custom manifold. .84 cold 1 hot .74 wheel.
water/meth may be a in the works later to step the boost up.
since no one compound boosts im not sure how the torque curve will look, but i would like to try and do as much to it now, so i can still do R&D but not a ton.

thanks for the information. once i get a little farther in I will start a build thread to show this motor and car coming together!

ivan93egreppin210

I have been wondering How much an f23 block can hold as well

q16racer

dont you love it when you post good info and it goes in one ear and out the other?

ShazYyY

Im building a G23 motor with a h22 head and f23 block..ive got h22 type S pistons with me and boring the f23 block to 87mm..what should be my piston to wall clearance for a n/a setup..im looking for 14++ compression..

Ive done the same project before but my main bearings got fu**** up maybe because of a faulty oil pump..plus my pistons were damaged to from the side..Looking for a safe piston to wall clearance..

I got 285 compression on the compression test..Dont know how much that measures to in Cr.