Ok so i'm planning my G23 setup Here is what I have and opinions and data is much appreciated.

So to start off... i'm copying Pirates setup since it's known good.

-F23 bottom end bored to 87mm
-H22A4 Pistons putting me at about 11.7:1 compression*
-Crower St. 2 Cams
-RM springs/retainers
-Stock Valves
-Cam gears.. yeah
-DC Header and custom 2.25 crushed exhaust with flowmaster
-Mild port and polish plus 3 angle valve job
-No AC
-Lightweight flywheel + Exedy OE clutch
-Keeping BS and PS
-P74/75 ECU with chrome/uberdata/neptune... whatever

I live at between sea level and 500ft so... yeah tuning..

still need advice about injectors and whatever I missed. Thanks for looking and all the help. I've tried to do my research and i'm sure there is plenty of stuff I've missed.






Modified by darkspector2.0 at 10:02 PM 8/29/2006

 

so um, whatcha going to do about the pistons sticking out .042"? it will be interesting turning it over for the first time once it's all assembled.

and get the 2.5" exhaust. My old 2.25 crush-bent robbed me of midrange torque.

Pirate

 

well... ok recessing the CC gotcha I just forgot to mention it

and now i'm thinking.... I want streetable with more low end... would st. 2 cams be better than st. 3?


Modified by darkspector2.0 at 1:35 AM 8/29/2006

 

I would use different pistons. You can make up the difference with RSX pistons. Get some 86.25mm USDM type-S pistons and then you do not have to touch the head to get it to clear. I do not think that you want to use the H22's. I did it becasue I was cheap and just threw the motor together. I never expected the engine to last but it has. It works great. It'd work even better with 'better' pistons.

If you want better low end/midrange then I would recommend the stage 2's. I would say that the stage 3's are not for everyone.

Pirate

 

How much of a difference in power would that .75mm make?

 

looks like a good setup, like pirate said don't use the a4 pistons. if you want to go 87mm then i suggest some custom pistons with the correct 1.181 compression height and that are lighter than stock a4 pistons.

if you want to go a4 pistons and bore out the combution chamber then go for it, pirates seems to be holding together nicely

edit: you didn't say whether this was a h22 or h23 head.

if it were me and it s a h22 head i would go for the stage 3s

 

sorry, it's an h23 head.... I don't plan on being up in the 5-6k rpm THAT much... so I was thinking something that would bring the power on sooner would be good. Afterall it will be a DD and then SOME autocross maybe road race later.

 

low and midrage is all in stroke. so you off to a good start. if your not going to be too rev happy then h22 pistons might be ok, we will see what pirate says. i often talk to him about his setup and how he wishes the h22 pistons wern't so heavy. and turning the G23 to high rpms on the toothpick rods is dangerous

 

from my research just now.. unless it was wrong info

the k24 pistons are 87mm and are 10.5:1 with the same compression height. So does that mean the motor will be 10.5:1

 

Supposedly the k24 has a 50.5 cc chamber, 87mm bore and 99mm stroke. So if you give it a 97mm stroke and a slightly smaller chamber then it will still drop compression a little bit. About down to 10.38:1 by my best guess. But you can bump the compresison back up to 10.87:1 with a .020 mill and you can throw in some flat faced valves to bump a little more. I am not sure what it would cost to do all that but it just seems easier to get some custom forged pistons that are meant to do what you want to begin with.

But with a little work I would guess that the K24 pisons will work better than the H22s. Not too sure about the valve pockets but I would guess that it's alright. I would clay to be sure though.

Pirate

 

I've got a 5k budget and I don't want to hit anywhere near that with 20% intrest... so I'm trying to keep cost down while maintaining a good build. Hard to do yes... impossible no...

So... in a previous thread I read someone getting a quote for custom CP pistons for this setup for $500. Didn't see much about it... did anyone have more info on that?

To be honest I'm not really sure what to ask for when ordering custom pistons. I'd like to stay at about 12:1.

 

Ok so now i've been thinking... I can order a K series spec piston, then ask them to use an H series valve relief then order it... 12:1

That would be... 11.88:1 I think

Think im' gonna call CP and see what they can do.

 

Or make it more simple and ask for an 87mm H23 piston with a 1.181" compression height, 1.75cc dome and a floating pin. You are using the H23 cylinder head right?

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">Or make it more simple and ask for an 87mm H23 piston with a 1.181" compression height, 1.75cc dome and a floating pin. You are using the H23 cylinder head right?

Pirate</TD></TR></TABLE>

if going with custom pistons , this is the best idea yet

 

I think honda's "floating pin" is different than an aftermarket 22mm floating pin by 0.001" so that would be something to check. Worst case you have modify the rods slightly to fit the piston pins, which is not too expensive.

Here is a thought: If you are going to rebuild the head and get new valves anyway, you could get Pirate's H23 head with bent valves and use that. It already has the chambers cut for H22 pistons.

Another thought: Pirate actually had better low end torque with the stock H23 cams vs the Crower stage 3's. If this is what you're after, it might not be a bad way to go, and you could save on springs/retainers too.

Final thought: Pirate's original build was VERY low budget. If you really have a $5k budget, why not do a VTEC build?

Good luck on the project.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">Or make it more simple and ask for an 87mm H23 piston with a 1.181" compression height, 1.75cc dome and a floating pin. You are using the H23 cylinder head right?

Pirate</TD></TR></TABLE>

What would the compression be with that... i'm on the phone right now with Camp1320

 

I can get a h23 spare head for $150 locally, and he'll probably let me take the block too if I want. I have 5k to spend but I really don't want to spend it all... and VTEC get's expensive

Just talked to Camp or Cap... whatever.. they said $595 for custom full kit.. rings, pistons, wrist pins, locks.. the whole 9 so to reasses what i'm going to use

-F23 Block, 87mm Bore
-H23 Head
-Mild port
-3 angle valve job
-Stock valves
-RM Springs and Retainers
-Crower St. 2 Cams
-CP Pistons forged 87mm, 1.181 CH, Wrist pins for stock rods, 1.75cc Dome, 11.8:1
-Fidanza 8lb flywheel and Exedy OE clutch

-Cam gears, P75 ECU for tuning, No AC

So.. now if the piston situation looks good... need to get the fuel situated what size injectors would you recommend, then I'll need a FPR and fuel rail.. fuel pump?


Modified by darkspector2.0 at 12:18 PM 8/30/2006


Modified by darkspector2.0 at 12:18 PM 9/2/2006


Modified by darkspector2.0 at 12:18 PM 9/2/2006

 

With the piston specs I listed you will be real close to 11.8:1 assuming nothing is milled and you run a Honda headgasket.

IMO you do not need anything but a FPR and some Prelude 345cc/min injectors. If you make like 220whp then you should look into some 370-440s. The pump and fuel rail are unnecessary.

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">With the piston specs I listed you will be real close to 11.8:1 assuming nothing is milled and you run a Honda headgasket.

IMO you do not need anything but a FPR and some Prelude 345cc/min injectors. If you make like 220whp then you should look into some 370-440s. The pump and fuel rail are unnecessary.

Pirate</TD></TR></TABLE>

Sweet man!!!! I'm soo excited I should be ordering my parts in the next few days!

 

So... I was thinking... If i'm ordering custom pistons anyways.. and I'm boring the cylinders out anyways... what's keeping me from going 88mm or even 89mm

with an 88mm bore I'd be at about 2.36l
and with an 89mm bore I'd be sitting at about a healthy 2.41l displacement. I'm liking that idea!


and i wonder what this is gonna do to my emissions I live in washington.. not too strict


Modified by darkspector2.0 at 9:54 PM 9/6/2006

 

The iron sleeve insert is only .080" thick on the F23. For every millimeter that you overbore the cylinders you take .020" off that thin little sleeve. I thought I was taking a risk by overboring 1mm. Seems to work I'll admit. Maybe you can try 1.5 or 2mm, I'll be happy to let you be the guinea pig on that.

If you want a 2.4l then pony up the dough for some real sleeves and then you'll be set for anything you throw at it.

Emissions will be greatly affected by cam selection, especially since you do not have VTEC. With an efficient catylitic converter, conservative timing, and stage one or two cams I do not think that it would be difficult to pass emissions. Of course it will be harder to meet idle RPM emissions with more agressive cam profiles.

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">The iron sleeve insert is only .080" thick on the F23. For every millimeter that you overbore the cylinders you take .020" off that thin little sleeve. I thought I was taking a risk by overboring 1mm. Seems to work I'll admit. Maybe you can try 1.5 or 2mm, I'll be happy to let you be the guinea pig on that.

If you want a 2.4l then pony up the dough for some real sleeves and then you'll be set for anything you throw at it.

Pirate</TD></TR></TABLE>

Point taken that's why i asked. So realisticly you wouldn't even go past 87. Mkay... good to know

 

In to find out what you did.

Question to OP. Why not keep 86mm sleeves for now? and F23 head gasket is oem at 87mm so to bore over that you would run into HG sticking into the quench area?

Otherwise I will be doing this hybrid motor this winter.