ok, I finally aquired an S2000 piston and compared it to a Type S. pin height is the same as the on both but the F20's is wider and H22&H23 rods will have to get machined to accomadate the wider pin and wedge the small end side to fit the rod. F20 piston is smooth to the touch compared to the Type S I couldn't weight the pistons (don't have a scale yet), the F20 rod is longer than both the H23,H22 and also is ticker and heavier. valve reliefs on the ex. and In. look about the same zise as the H's slugs. comments and questions are welcome..

ring lands are the same size except for the oil control on the F20 is a few 1/000's bigger.



RODS. H23 H22 F20

F20 small end wedged

F20 top

F20 top

USDM top H22

Type S top





Modified by Qfactor at 10:07 PM 12/5/2003


Modified by Qfactor at 10:08 PM 12/5/2003

 

So are you gonna do it or what?

 

Yea man, do it. Theres no solid proof out there as of now if it could be pulled off.

 

Curiousity is getting the better of all of us. There has been many 'I think', 'I have done the math' statements out there, put this subject to rest and try and pull it off, then measure the compression to see what it would be. This would be invaluable info for H.

 

in the old thread Satan mentioned what the CR would be w/ these......what is it again?

Also, the only real way you're gonna figure anything out is to take one and get it machined, throw it on a rod and stick it in a motor. Turn it over and clay it so you can see if it's hitting anything, and let us know!

 

Were you comparing the rod from a h22 or h22a4 versus the f20 rod?
I ask because the h22a4 in the 5th gens use a full floating pin, and may match the f20 closer if you were using a rod from a 4th gen.

 

good info.

 

also,fron the looks of the side shots of the pistons,it looks like the h22 piston has bigger oil control ring lands then the f20 does.

 

are you sure that the pin height is the same, did you measure from the pin to the top of the piston

http://ef-1.zeroforum.com/zerothread?id=806

that thread says that the piston pin height is different.

 

I will put the F20 piston on an H22 block and clay it and check piston to valve clearance, piston height. will keep you posted..

 

you could measure the pin diamiter of the f20 then divide by 2, then measure from the top of the pin hole to the side of the piston, then add the radius of the pin to that number and do the same for the h22 , did you look at the link i posted?

 

All i see id the little red X.

 

this is interesting, i am waiting and curious. The plot thickens

 

Well,i guess also we can rule out the theory that the s2000 pistons are forged,cuz they do not look like Forgings,but just a higher quality casting.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aeolus &raquo;</TD></TR><TR><TD CLASS="quote">Well,i guess also we can rule out the theory that the s2000 pistons are forged,cuz they do not look like Forgings,but just a higher quality casting.</TD></TR></TABLE>

how do you figure that?

 

http://www.vtec.net/forums/one...46496
http://www.automotiveforums.co...83217
http://www.motoringlife.ie/honda_s2000.htm
http://forums.skylinesdownunde....html
http://www.honda.co.uk/brochur...0.pdf
http://www.autospeed.com/cms/A_1127/article.html
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">To achieve this level of performance it uses formula one inspired technology with forged aluminium pistons, lightweight valve springs and roller rocker arms produced by metal injection. </TD></TR></TABLE>
everyone and their mom seems to think they are forged, im currently looking for some hard evedence

edit: there is your proof, im sick of copy and pasting urls


Modified by prelittlelude at 1:19 AM 12/8/2003

 

We had a big post on Ef-1.com bout this..

http://ef-1.zeroforum.com/zerothread?id=806

 

wasnt the compression hight different or something. i remember something about it not coming all the way up in the cylinder. you needed longer rods, which would make for a better r/s ratio. search its in here.

 

Ok, I have some stupid questions so please don't flame. What is decking the block? Why are these forged pistons frm friendly as opposed to other forged pistons? Also, wouldn't it be cheaper to have a set made that would both raise c/r and r/s?

 

Decking is basically milling. The theory is that since the S2000 has FRM sleeves the pistons would also be safe to use with our FRM sleeves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by racerx &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I have some stupid questions so please don't flame. What is decking the block? Why are these forged pistons frm friendly as opposed to other forged pistons? Also, wouldn't it be cheaper to have a set made that would both raise c/r and r/s?</TD></TR></TABLE>
millng is done to the head, decking is done to the block. the idea in the threa on ef-1 is that the piston is a bit shorter than the h22, and in order for the s2k piston to reach proper deck height in an h block without using a custom longer rod you need tot ake material off of the block. i don't know why their forged pistons are frm compatable. and i don't know how we would duplicate what honda did if we don't know what they did in order o make a set of our own.

but what it hink everyone should look into is the 2004 s2k with a 90.7mm stroke and 87mm bore that has forged pistons.

 

notice the huge skirt on the s2k piston....i bet it has all to do with how it works.....

 

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

how do you figure that?</TD></TR></TABLE>

If it was a forging,it would not have the protruding lettering on the top of the piston or the valve reliefs without them having to be machined out.That can only be acheived on a cast piston.They could even be a high pressure die cast peice.i really doubt honda would use forged pistons on a production car that is expected to last 100,000 or more miles.now i admit,i could be wrong on this,but i havent seen or heard any hard evidence that they are definitely forged.Having pistons forged like the way the s2000 pistons are would be expensive.


Modified by aeolus at 9:18 AM 12/9/2003


Modified by aeolus at 9:33 AM 12/9/2003