https://honda-tech.com/zerothread?id=1232811

has almost everything you need for compression calculations....when you dont know the compression...so flyrod's page wont help here....

UPDATED

ccs for each piston :
usdm h22 : -2.0 cc
jdm h22 : 1.7cc
type s h22 : 3.9cc
usdm h23 : ????

now all we need is compression height on the type s...

i have been trying to calculate compression for a f23 hybrid/type s pistons....for myself....i dont trust the estimates....nor do i trust pump gas....

thanks gentlemen.....and yes this is also posted in all motor.....


Modified by mgags7 at 3:34 PM 10/20/2005

 

I can tell you that there is a huge difference in compression height on the F23 and H22 pistons.
F23 1.181" CH
H22 1.223" CH

Pirate

 

is there any page with that on it or is that from your cabeza??

thanks duder...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">is there any page with that on it or is that from your cabeza??

thanks duder...</TD></TR></TABLE>

he measured them when he was putting together his g23

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">i have been trying to calculate compression for a f23 hybrid/type s pistons....for myself....i dont trust the estimates....nor do i trust pump gas....</TD></TR></TABLE>

well...i dont know what it exactly is but it wont be for the street....

 

Type S pistons will have the same issues in F23 as Pirate had with regular H22 pistons:

https://honda-tech.com/zerothread?id=1046336

Type S pistons are the same as other floating pin OEM H22 pistons, just with a higher dome that raises compression. Pirate was at about 12.3:1 with the USDM pistons, so Type S would put you in the 13-15 range depending on what you do for a head...

 

Well I measured those pistons and that is what I remember. If you like I can get real **** ad re-measure it with one of these:

http://faro.com/products/gage.asp

It is supposedly accurate to .0002" but I might think that it is a bit overkill. The numbers I posted are pretty accurate. You will still need to measure everything to get accurate measurements for your build. The deck height has a tolerance window that can either be taller or shorter as with the rods and the crank pin offset etc. So your actual results may vary slightly from mine and so forth...

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">i have been trying to calculate compression for a f23 hybrid/type s pistons...</TD></TR></TABLE>

Of course Type-S pistons are still heavier than stock F23 and that stresses the rods even more than usual. If I was to put together a high revving F23 hybrid or H22 with F23 crank/rods I would keep the stock rods and shell out the money necessary to drop 100g of mass off the pistons. If you do that you can safely rev to 7450 rpm all day long and have less vibration, more power, custom compression, no piston to head or piston to valve issues, etc.. If you use the F23 block it already has Iron sleeves to that facilitates the use of forged pistons too.

If you want to safely rev higher than 6500 then you might see if ARP, Crower, or AEBS, etc. make rod bolts for the K20A3 base model Acura RSX as the rod bolts are the same:

K20A3: 13204-P8A-A01
F23A1: 13204-P8A-A01

But I still would worry about taking it up to 7500 all the time. Lighter pistons are the way to go IMO.

Sorry for the double post.
Pirate

 

hey thanks for the help...and lighter pistons are definitely needed if i want to rev it....and you know i do

i talked with rick solis about it for a while and he said he could get me some wisecos that used the alloy thats compatible with the frm and they would be damn light....thats the way im gonna go when i do this...

i might even end up getting the journals modified to fit some custom length b series i beam rods...lighten things up even more....

nobody can get all excited yet though....this wont be until late next summer...

 

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

Of course Type-S pistons are still heavier than stock F23 and that stresses the rods even more than usual. If I was to put together a high revving F23 hybrid or H22 with F23 crank/rods I would keep the stock rods and shell out the money necessary to drop 100g of mass off the pistons. If you do that you can safely rev to 7450 rpm all day long and have less vibration, more power, custom compression, no piston to head or piston to valve issues, etc.. If you use the F23 block it already has Iron sleeves to that facilitates the use of forged pistons too.

If you want to safely rev higher than 6500 then you might see if ARP, Crower, or AEBS, etc. make rod bolts for the K20A3 base model Acura RSX as the rod bolts are the same:

K20A3: 13204-P8A-A01
F23A1: 13204-P8A-A01

But I still would worry about taking it up to 7500 all the time. Lighter pistons are the way to go IMO.

Sorry for the double post.
Pirate</TD></TR></TABLE>

good info as always...i learn so much from you

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">hey thanks for the help...and lighter pistons are definitely needed if i want to rev it....and you know i do

i talked with rick solis about it for a while and he said he could get me some wisecos that used the alloy thats compatible with the frm and they would be damn light....thats the way im gonna go when i do this...

i might even end up getting the journals modified to fit some custom length b series i beam rods...lighten things up even more....

nobody can get all excited yet though....this wont be until late next summer...</TD></TR></TABLE>

Check out Mahle too. They have an FRM compatible piston. It's suppose to be high in silicone content to reduce expansion along with the skirt coating like weisco's. Mahle is a HUGE company that is the OE to many many companies around the world. They are known for quality products.

But you don't need them with the F23 .

 

I have custom pistons done up for my G23VTEC... I might be able to send you the specs if youre interested. Might be hard to get my engine builder to release the information. He did have to have the wrist pin moved (up or down?) to lower the compression height though. Still reallllly high compression though.

 

Even though the pistons are lighter, do the bearings not hold back the rev'vability of the f23 bottom end?

 

I would imagine that power output is a greater factor concerning the longevity of he F23's rod bearings. But on other forums people are turboing the F23 in stock trim to 300 hp and doing so for a while. I would imagine that 220whp NA could cause trouble after a lot of hard miles but would be less stressful than a turbo setup. You can help curb the bearing abuse with higher oil pressure and 40w oil.

Pirate

 

has anyone tried what rick suggested a while back...

grind out the journals to fit wider rods, like some b series, because those would be easy to find in almost any length...

this seems like a good solution to the bearing problem, along with some upgraded hardware (arp, etc) im thinkin it would last pretty well at 220whp...but who knows until its done

 

2point6 is the only one I know of. And he has not swapped in that engine yet IIRC.

We still do not know if the F23 rods and bearings are actually a concern. This F23 Hybrid stuff is pretty new around here. But at what point is it a point of diminishing returns? If people keep using the F23 block replacement components are pretty damn inexpensive. Spin a bearing? replace the crank/rod/block. Egg a cylinder? Replace the block with new rings and a fresh hone...

Also, I suppose that torque is a better unit of measure to predict longevity of the rod bearings. Horsepower is just a function of torque and rpm. So If you make 220hp at 4000 rpm (289 ft/lbs torque) the bearings will experience higher loads than 220hp at 8000 rpm (144 ft/lbs torque). Of course ignition timing can greatly affect bearing wear. Detonation will kill longevity on any bearing.

Pirate

 

Yeah the rod bearings are a concern with my setup. I will be running thicker oil like you suggested... I IM'd a guy who has an F23/H22 combination and he said he took it to 7500 many times and had no problems...

I might go higher, max 8000... My pistons are skirtless (forgot the weight, in the low 300 grams range IIRC), I'm using Crower rods (are they lighter?, I don't know), the assembly has been balanced, and a Fluidyne harmonic pulley is being deployed, so this engine should be pretty smooth, which should help out the rod bearings even more.

Sorry to get off topic mgags, perhaps you should try emailing Jeff @ Importbuilders, he might know dome sizes for H's. He's had 2 personal H23VTEC vehicles.

 

awesome info pirate

 

head, that motor sounds nice....

and good info pirate....i agree that the f block isnt the cheapest way to go, why arent more people trying the h block??
does anyone have any idea what the compression would be like with an h23 piston??

 

head, what compression are you going with? instead of a custom compression height pistons, wouldnt it have been easier/better to just use some high compression k20 pistons? sounds like your getting into a fun motor

 

^^his pistons are super light thats why he went custom....everyone look up top, i found the cc for the type s, jdm, and usdm h22....

 

anyone want to teach me about this compression height and the other junk you are talking about. I'm not quite familiar with it. Sorry to go kinda OT, but its still kinda on topic

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SB tuning &raquo;</TD></TR><TR><TD CLASS="quote">head, what compression are you going with? instead of a custom compression height pistons, wouldnt it have been easier/better to just use some high compression k20 pistons? </TD></TR></TABLE>

Looking back on things, I probably would have gone with K pistons, but at the time it had not occured.

Static compression is really high, over 12:1. Actually, I am not supposed to give away the actual compression. We are looking for a replacement starter, its that high. But, the motor will only see 99 octane fuel

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">^^his pistons are super light thats why he went custom....everyone look up top, i found the cc for the type s, jdm, and usdm h22....</TD></TR></TABLE>

What is your source? I was told 7 cc by Jeff.

I also played with the B-series compression calculator, but plugged in H series specs. I did not know H headgasket thickness, or piston to deck height, so I just used B series numbers there. I came closer to 11:1 with a 7 cc dome then with a 3.9 cc dome.

I am sitting in a hotel room, bored. Sorry to stir the pot

 

hey i like this thread

im going to have to remind everyone that when pirate did his build he had to bore out his cylinder head alittle because of the rediculously close tolerences that using an h22 piston created. using a type s piston has even a larger dome..

so you guys know i use http://www.c-speedracing.com their compression calculator is cool, but of course they have no specs for the h series or even F

just also like to toss in that the s2000 has stock frm compatable pistons that are forged, and have 1.181 compression height mat 87mm bore.

edit:

as far as the compression height on the type s pistons go it would be the same as all other h22 pistons because they all use the same crank and rods in the same block , so in order to reach proper deck height the compresion height must be 1.223 like pirate said.