mgags7

I am attempting to make a thread explaining every possibly block and crank/rods and pistons combo motor, all oem stuff.

This is all assuming stock 87mm bore and oem headgasket. I didnt do anything with the f series pistons, i didnt feel it necessary to ever use those.

All figures in inches unless otherwise denoted

Every h and f block has the same deck height of 8.643 inches, you can use either block if you want, but frm blocks are lighter

<FONT SIZE="4">props to prelittlelude and piratemcfred they were the guys that innovated all this stuff</FONT>

<u>Crank/Rod Options</u>
H22 - 90.7mm stroke - 5.633 rod length
H23/F22 - 95mm stroke - 5.572 rod length
F23 - 97mm stroke - 5.551 rod length

<u>Piston Options </u>
USDM H22 - 1.221 compression height / -2.0cc dome
JDM H22 - 1.221 compression height / 1.7cc dome
H22 Type S - 1.221 compression height / 3.9cc dome
USDM H23 - 1.203 compression height / -10.5cc dome

<FONT SIZE="2"><u>OEM Piston Swaps</u></FONT>
H22
Compression Ratio with:
H23 Pistons: 8.52:1
USDM H22 Pistons: 10:1
JDM H22 Pistons: 10.6:1
H22 Type S Pistons: 11:1

H23
Compression Ratio with:
H23 Pistons: 9.8:1
USDM H22 Pistons: 11.67:1
JDM H22 Pistons: 12.47:1
H22 Type S Pistons: 13.01:1

<FONT SIZE="3"><u>COMBOS!!</u></FONT>

<u>The classic h23 vtec:</u>
Head: H22 Vtec
H23/F22 Crank and Rods
95mm stroke * 87mm bore = 2258.9cc

Compression ratio with:
h23 pistons: 9.3:1
usdm h22 pistons: 10.5:1
jdm h22 pistons : 11.1:1
h22 type s pistons: 11.53:1

NOTE: From here on out, the f23 crank and rods are used, with any factory h series piston there will be not only piston to valve clearance problems, there will be piston to head clearance problems, careful consideration of headgasket thickness and head chamber machining must be taken.

Also, dont think that the thin as ***** stock f23 rods and stock hardware are gonna take anything more than 6800 rpm, becuase they will commence self-dissasembly at and above this rpm level. Get some aftermarket rods and hardware if you need high rpm with this motor....

<u>F23 DOHC Vtec</u>
Head: H22 Vtec
F23 Crank and Rods
97mm stroke * 87mm bore = 2306.5cc

Compression Ratio with:
USDM H23 pistons: 9.86:1
USDM H22 pistons: 11.72:1
JDM H22 pistons: 12.51:1
H22 Type S pistons : 13.04:1

<u>G23 Non-vtec</u>
Head: H23 non vtec
F23 Crank and Rods
97mm stroke * 87mm bore = 2306.5cc

Compression Ratio with:
USDM H23 pistons: 10.41:1
USDM H22 pistons: 12.53:1
JDM H22 pistons: 13.46:1
H22 Type S pistons: 14.08:1 (lol wow)

whew....put your pencils down....

If I messed up anything let me know, i just did a lot of calculations, i probably messed something up....

Ps. <FONT SIZE="10"><FONT COLOR="red">I HOLD NO LIABILITY IF YOU BUILD SOMETHING ACCORDING TO THIS AND RUIN IT. That would be your own damn fault for not doing enough research</FONT></FONT>


Modified by mgags7 at 12:59 PM 1/4/2006

prelittlelude

hey this is great thread , the most important thing is that piston to deck height when doing calculation can mess everything up. i think this is a great start, but i haen't taken the time to go and calc all the ratios . Im sure matt alot of urs are right, but like you said its up to the person to make the final check.

plus alot of different things can be done to chage compression ratio. from milling the head, decking the block or changing out pistons which obviously this thread highlights.

the biggest plus is that with any F block aftermarket forged pistons can be pruchased and installed to reach any desired c/r

The Birdman

nice work matt!!

Dont forget the f23 block with rsx pistons....

shutta

nice. I'll have to add this info to my folder of prelude related stuff. (yeah, I'm a dork like that) how exactly did you calculate this all out?

mgags7

compression ratio is the ratio of volume of the combustion chamber when the piston is at bottom dead center to the volumne at top dead center

so i factor in all the heights and the ccs of the piston dome and head chamber to figure out the volume at tdc, and use the same for bottom dead center....pretty involved for each calc....

so i make it easier and use a calc
http://www.zealautowerks.com
haha

prelittlelude

the f23 and f20c and k20 have a 1.181 compression height

some people put the k20 rsx pistons in a bored out f23

you can't take a f23 that is bored to 87 and just put any h series piston in it. well the h23 piston might be possible but if you use any h22 piston there will be piston to head contact. refrence piratemcfred's thread where he had to bore the combusion chambers in order for proper clearence. so this would change your c/r depending on how much material you take out of the head. also remember that runing a 1.221 compression height h22 piston in a f23 block which usually has a 1.181 compression height piston in it will result in a difference of .04 in piston to deck clearence. so what ever the piston to deck clearence is with a stock f23 piston you will now be .04 higher.

high_revs

very good info...im doing k20 type s pistons in my f23....11.9:1 compression

unuselectus

What about numbers for piston choices in a f22a block with a f22a head?

98vtec

that would not be a hyrbid....

i cant believe i missed this thread was not put in the faq, its going in tonight.

oem_certified_accord

that calculator works wonders

Si Speed

Very useful thread.
Question though, if someone was on a budget build, but still going for reliability, how good of an idea would it be, to use Type S pistons and shave the head in order to raise compression slightly if someone didn't want to (or couldn't afford to) sleeve their block for higher compression pistons? Also, how much of the head could be shaved safely and what kind of compression would it yield? Assume OEM sized valves would be used.

Si Speed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Si Speed &raquo;</TD></TR><TR><TD CLASS="quote">Very useful thread.
Question though, if someone was on a budget build, but still going for reliability, how good of an idea would it be, to use Type S pistons and shave the head in order to raise compression slightly if someone didn't want to (or couldn't afford to) sleeve their block for higher compression pistons? Also, how much of the head could be shaved safely and what kind of compression would it yield? Assume OEM sized valves would be used.</TD></TR></TABLE>

Bump for an answer please.

oem_certified_accord

here you go: https://honda-tech.com/zerothread?id=776837

that should answer all your ?'s

vinuneuro

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Si Speed &raquo;</TD></TR><TR><TD CLASS="quote">Very useful thread.
Question though, if someone was on a budget build, but still going for reliability, how good of an idea would it be, to use Type S pistons and shave the head in order to raise compression slightly if someone didn't want to (or couldn't afford to) sleeve their block for higher compression pistons? Also, how much of the head could be shaved safely and what kind of compression would it yield? Assume OEM sized valves would be used.</TD></TR></TABLE>

If you want more compression than the Type S, get the Mahle Goldseries 11.5:1 pistons. They're frm compatible. Shaving the head too much will create unnecessary problems.

Si Speed

Thanks Accord dude. I'll see if I can get some answers there.
Vinuneuro, I've heard that many people have run into problems with those. I wouldn't want the final compression far past 11.5:1. I'm just looking at all possible routes.

THC07

Any of you know somone with an H23V2B? Id love to see some pics.

ethereal2pt2

great stuff man. this will definitely come in handy later down the road. thanks. let's keep the info coming.

vinuneuro

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Si Speed &raquo;</TD></TR><TR><TD CLASS="quote">Thanks Accord dude. I'll see if I can get some answers there.
Vinuneuro, I've heard that many people have run into problems with those. I wouldn't want the final compression far past 11.5:1. I'm just looking at all possible routes.</TD></TR></TABLE>

They work fine. Many people have used them successfully. Get the pistons and leave the compression at 11.5:1 instead of raising the comp by the halfassed method of milling.

Si Speed

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

They work fine. Many people have used them successfully. Get the pistons and leave the compression at 11.5:1 instead of raising the comp by the halfassed method of milling.</TD></TR></TABLE>

Well, like I said, I'm still researching everything. I still am leaning towards resleeving and going that route. I just think that if the pistons you mentioned were so good, more people would do that instead of sleeving and getting all new internals. That's for reminding me though. I actually had forgotten about them.

What's half assed about shaving the head? That used to be one of the only ways people could get power. I just know I wouldn't get any of the shops around here to do it. I had one tell me I'd need at least 104 octane to run 11:1 compression when I mentioned Type S pistons.

98vtec

resurfacing the head to make it flat is one thing, but i am completely against milling the head just to gain compression. If, later on, you decide to kick it up a notch, you will be limited due to the drop in the amount of space to work with.

vinuneuro

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

Well, like I said, I'm still researching everything. I still am leaning towards resleeving and going that route. I just think that if the pistons you mentioned were so good, more people would do that instead of sleeving and getting all new internals. That's for reminding me though. I actually had forgotten about them.

What's half assed about shaving the head? That used to be one of the only ways people could get power. I just know I wouldn't get any of the shops around here to do it. I had one tell me I'd need at least 104 octane to run 11:1 compression when I mentioned Type S pistons. </TD></TR></TABLE>

People use 12-12.5:1 static comression on pump gas easily.

Si Speed

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

People use 12-12.5:1 static comression on pump gas easily.</TD></TR></TABLE>

That's always been my understanding, that it's nearly impossible to go past 12.5:1 on 93. Good thing about not having money, leaves plenty of time to research and make sure I do get it right, Problem is, actually making a decision when I am ready. But let's get back on topic. /threadjack

Dxavier125

nice thread that calculator is dopee

bluedlude

just wanted to add for anyone thinking about using an F20C piston. the valve reliefs are pushed out toward the cylinder wall farther than on an H22/H23 piston so machining would have to be done to make them work.

great thread matt

BlkChryKord

Anyone came across this combo yet besides myself? I got everything pretty much free minus the head and rods for under $300.

H22a4 Block (needs sleeved), F23 crank (spare), H23 head, F23 IM (spare), Eagle K20 .30" longer (146mm) Rods.

I figure if I ever get it together that I'll def need custom pistons b/c of the longer rod length. Good N/A or boost motor? I was leaning more towards boost...